Hi everyone, I'm facing an issue with an Azure Logic App (Consumption) that uses the "When a HTTP request is received" trigger. Environment Azure Logic App (Consumption) Trigger: When a HTTP request is received HTTP Method: POST Trigger access: Any IP Azure Automation is called later in the workflow (not at the trigger stage) Issue The Logic App callback URL works correctly when tested from Postman using a POST request. However, when the same callback URL is invoked from a UKG Ready Webhook , UKG consistently receives HTTP 401 Unauthorized . The Logic App workflow is not triggered , so no run history is created. What I've already verified The callback URL configured in UKG is identical to the Logic App callback URL. The URL includes all generated query parameters ( api-version , sp , sv , and sig ). The trigger method is POST. Trigger access is configured as Any IP . UKG webhook authentication is configured as No Authentication . The same callback URL works successfully from Postman. Azure Logic App diagnostics do not report any trigger or authentication issues. UKG Support has confirmed their webhook feature is working correctly and suggested investigating the Azure Logic App endpoint. Question Has anyone experienced a scenario where the Logic App callback URL works from Postman but returns 401 Unauthorized only when invoked by another application (in this case, UKG)? Are there any additional Azure diagnostics, trigger settings, or authentication checks that could explain this behavior? Any suggestions would be greatly appreciated. Thank you!

Azure Logic App HTTP Request Trigger returns 401 Unauthorized when invoked by UKG Webhook, but works from Postman

Sudeep Pandey 0

Hi everyone,

I'm facing an issue with an Azure Logic App (Consumption) that uses the "When a HTTP request is received" trigger.

Environment

Azure Logic App (Consumption)
Trigger: When a HTTP request is received
HTTP Method: POST
Trigger access: Any IP
Azure Automation is called later in the workflow (not at the trigger stage)

Issue

The Logic App callback URL works correctly when tested from Postman using a POST request.

However, when the same callback URL is invoked from a UKG Ready Webhook, UKG consistently receives HTTP 401 Unauthorized.

The Logic App workflow is not triggered, so no run history is created.

What I've already verified

The callback URL configured in UKG is identical to the Logic App callback URL.
The URL includes all generated query parameters (api-version, sp, sv, and sig).
The trigger method is POST.
Trigger access is configured as Any IP.
UKG webhook authentication is configured as No Authentication.
The same callback URL works successfully from Postman.
Azure Logic App diagnostics do not report any trigger or authentication issues.
UKG Support has confirmed their webhook feature is working correctly and suggested investigating the Azure Logic App endpoint.

Question

Has anyone experienced a scenario where the Logic App callback URL works from Postman but returns 401 Unauthorized only when invoked by another application (in this case, UKG)?

Are there any additional Azure diagnostics, trigger settings, or authentication checks that could explain this behavior?

Any suggestions would be greatly appreciated.

Thank you!

Vallepu Venkateswarlu 10,260 Reputation points Microsoft External Staff Moderator

2026-07-03T16:01:30.2466667+00:00
Hi Sudeep Pandey,

It sounds like you've done a thorough job narrowing down the issue. Let's walk through some additional troubleshooting steps and considerations specific to Azure Logic Apps HTTP triggers and webhook integrations.

Possible Causes for 401 Unauthorized Since your Logic App trigger works from Postman but returns 401 Unauthorized from the UKG webhook, the issue is likely related to how the request is being made rather than the Logic App configuration itself.

Callback URL Integrity

Double-check that the entire callback URL, including all query parameters (api-version, sp, sv, sig), is being used by UKG with no modifications or encoding issues.

Some systems may inadvertently encode or truncate URLs, especially if they are pasted or stored in configuration fields.

IP Restrictions

You mentioned "Any IP" is allowed, but double-check the Logic App's Access Control (IAM) and network restrictions (e.g., VNET integration, firewall rules) that might block external sources.

Authentication Settings

Logic App HTTP triggers use the sig parameter for authentication by default. If UKG is adding its own authentication or modifying the request, it could cause issues.

Ensure UKG is set to No Authentication and is not adding any extra headers.
Sudeep Pandey 0 Reputation points

2026-07-03T16:05:48.35+00:00

Thank you for your suggestion.

I have already verified that the callback URL configured in UKG matches the Logic App callback URL, including the api-version, sp, sv, and sig parameters.

I also tested the same callback URL from Postman using a POST request, and the Logic App triggers successfully.

The issue only occurs when the request originates from the UKG webhook, where UKG receives HTTP 401 Unauthorized and no Logic App run history is created.

Would you recommend any Azure diagnostics or logging that could help determine why Azure accepts the request from Postman but rejects the request from UKG?
VEMULA SRISAI 13,715 Reputation points Microsoft External Staff Moderator

2026-07-03T16:06:18.1833333+00:00

Sudeep Pandey Thanks for your response.
Vallepu Venkateswarlu 10,260 Reputation points Microsoft External Staff Moderator

2026-07-03T16:11:03.51+00:00
Hi Sudeep Pandey

Thank you for the confirmation.

Could you please review the configuration below and confirm whether everything is configured correctly?

Authentication Settings

Logic App HTTP triggers use the sig parameter for authentication by default. If UKG is adding its own authentication or modifying the request, it could cause issues.

Ensure UKG is set to No Authentication and is not adding any extra headers.

Request Body Format

If the Logic App trigger expects a certain JSON schema and UKG sends a different format, it should not cause a 401, but malformed requests can sometimes trigger unexpected errors.

Try sending a minimal body from UKG (or even an empty body) to see if the error changes.

Additional Diagnostics

Enable Diagnostic Logging: In the Logic App, enable diagnostics for the trigger to see if any requests are being received or rejected at the platform level.

Check Azure Activity Logs: Look for any denied requests or security events around the time of the webhook attempts.

Test with Another Tool: Try using a simple script (e.g., curl or PowerShell) to POST to the Logic App URL to further isolate the issue.

If the above steps did not help resolve your issue, please feel free to share the details in a private message so we can proceed with further troubleshooting over a Teams call. I am happy to connect with you on Teams to investigate and resolve the issue.

Please "upvote" if the information helped you. This will help us and others in the community as well.
Sudeep Pandey 0 Reputation points

2026-07-03T16:11:20.4433333+00:00
Thank you for your suggestion.

I have already verified the following:

The callback URL configured in UKG is identical to the Azure Logic App callback URL.

The URL includes all generated query parameters (api-version, sp, sv, and sig).

The same callback URL works successfully from Postman using a POST request.

The Logic App trigger is configured to accept POST requests and allows Any IP.

Azure Logic App diagnostics do not report any trigger or authentication issues.

The issue only occurs when the request originates from the UKG webhook. UKG consistently receives HTTP 401 Unauthorized, and no Logic App run history is created.

UKG Support has also confirmed that the webhook functionality is working correctly on their side and recommended that we investigate the Azure endpoint.

Is there any Azure diagnostic logging or request tracing available for HTTP Request triggers that could help determine why Azure accepts the request from Postman but rejects the request from UKG?
Vallepu Venkateswarlu 10,260 Reputation points Microsoft External Staff Moderator

2026-07-03T16:12:46.2566667+00:00

Thanks for the update.

Can you please share the requested details in private message for further troubleshoot.
Vallepu Venkateswarlu 10,260 Reputation points Microsoft External Staff Moderator

2026-07-04T08:30:00.61+00:00
Hi Sudeep Pandey

I wanted to follow up regarding this issue.

Based on the information shared, the Logic App configuration appears to be functioning as expected, as the callback URL can be successfully invoked from Postman using the same HTTP method and signature. Since no Logic App run history is generated when the request originates from the UKG webhook, the request appears to be rejected before the workflow is triggered.

To continue the investigation, we would require the following information:

The complete HTTP request (URL, headers, and body) sent by UKG.

The complete HTTP response received by UKG, including any response headers (such as x-ms-request-id or x-ms-correlation-request-id, if available)

If possible, you may also have UKG send the same webhook request to a temporary endpoint (for example, webhooksite) to verify the exact request being transmitted.

At this time, we have not received any further updates. As there is no pending action from the Azure side and the requested information is required to proceed, I will go ahead and archive this support request for now.

If you are able to gather the requested details or the issue persists, please let us know by sharing the requested details. We'll be happy to continue assisting you.

Thank you for working with Microsoft Support.

Azure Logic App HTTP Request Trigger returns 401 Unauthorized when invoked by UKG Webhook, but works from Postman

Environment

Issue

What I've already verified

Question

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