Accessing Microsoft Dynamics online using Web API

Hi,

I am trying to access Dynamics CRM online using Web API, with authentication using the OAUTH 2.0 from Azure AD. Here is what I have done so far.

1. Registered my application in Azure AD in the App Registration.

2. Successfully authorize using https://login.microsoftonline/common end point. I am getting an Access Token and Refresh Token properly. I am also able to use the refresh token and get a new token. The resource I am passing to these is the Client ID of the application I registered.

3. I also configured Dynamics CRM Online (Microsoft.CRM) in the Required Permissions section of the application I registered.

Now, when I access Dynamics using the https://<mydomain>.crm.dynamics.com end point and access a resource (such as Account), I get a (401) Unauthorized error. This happens even with Postman application.

I have followed the steps in https://docs.microsoft.com/en-us/azure/active-directory/develop/active-directory-protocols-oauth-code

I also see another set of document - https://docs.microsoft.com/en-us/azure/active-directory/develop/active-directory-protocols-oauth-service-to-service

Is this relevant here for my use?

Thanks!

Venkat Rangan