403 Forbidden error in Postman calling dynamics o365 web api

Question

I am trying to call the dynamics O365 opportunity entity using web api. I registered an app in azure(same tenant) and created client secret key as well and added the same app as an application user in dynamics with system administrator privilege. Using the details such as 'OAuth 2.0 authorization endpoint (v1)', 'Client/Application ID' and 'Client_secret' I could get the access token and records from the entity without any issues using a console application. When I am giving the same details in Postman, I could generate the access token I am getting 403 Forbidden error.

{"error":{"code":"0x80072560","message":"The user is not a member of the organization."}}

grant_type:client_credentials

Answer 1

This can happen if the accessToken is incorrect or the registration is incorrect on the Dynamics side.

It could be that it is not the right accessToken for that user. Also, have you created the application users on the Dynamics side?

Authenticate with client credentials

S2S authentication.