Azure B2C: Access to Web API not working (401 Unauthorized)

Question

Dear Azure community,

I have a really hard time figuring out how to obtain access for a user to my Web API that is registered on a B2C tenant.

I use the ROPC policy, because it has to work without browser interaction, just with username and password. I managed to get an access token that I send in the header of my requests to the Web API, but I only get back "401 Unauthorized" no matter what I try.

Of course I'm aware that it is nearly impossible to find a solution without knowledge about my code and configuration and I also formulated a question containing more detailes to my problem on Stackoverflow (https://stackoverflow.com/questions/74479164/asp-net-core-web-api-azure-unauthenticated-error-access-token-in-header)

What reasons could there be that my access token is not accepted by the authorization? What reasons could there be that the access token is not valid? I really don't know what to try anymore :(

Any help on this would be highly appreciated! Thank you!

Answer 1

Hi @ManuBera ,

Thanks for reaching out.

I'm glad that you were able to resolve your issue and thank you for posting your solution so that others experiencing the same thing can easily reference this!
Since the Microsoft Q&A community has a policy that "The question author cannot accept their own answer. They can only accept answers by others", I'll repost your solution in case you'd like to "Accept" the answer so it will help others in community looking for similar issue.

Thanks,
Shweta