Thank you for posting this in Microsoft Q&A.
As I understand you have created about 180 users in Azure active directory. Now you want to sync all 180 users to on-premises Active directory that you have configured.
AD connect is the only tool that is used to sync object between on-premise AD and Azure active directory.
However, AD connect is always one way sync for objects (users, groups, contacts and devices). AD connect syncs objects from on-prem to Azure AD.
AD connect doesn't writeback user from Azure AD to on-premises AD. The user writeback preview feature was removed in the August 2015 update to Azure AD Connect.
This is also documented in our public document https://learn.microsoft.com/en-us/azure/active-directory/hybrid/how-to-connect-preview#user-writeback
Currently we do not have this feature. However, this might be one of our upcoming features in AD connect.
You can submit the feedback regarding this in our Azure feedback portal.
https://feedback.azure.com/d365community/idea/2f830ecc-ba25-ec11-b6e6-000d3a4f0789
This feedback is directly monitored by out product managers and they will be able to share any update on this if they have.
The only solution to you ask is to export users from Azure active directory and import them to manually to on-premise active directory using PowerShell scripts.
You can work with your scripting engineer in your organization and build a script to import them to on-premise active directory
Let me know if you have any further questions on this.
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