Jhon Elmer Bustamante Botero Thanks for posting your question in Microsoft Q&A. App registration is used to represent a client application and in case of multiple users, you can simply set up authentication and authorization with OAuth flows to an Identity Provider (for example, Azure AD). (No need for multiple app registration). The users need to obtain an access token from Identity Provider using OAuth flow and call APIM with the token in Authorization header. In Azure APIM, you can validate the token using validate-jwt
policy.
Here are some docs that can help you with this:
I hope this helps and let me know if you have any questions.