In order to generate an access token for a Microsoft resource, one needs to pass the "Resource" value in the token generation request.
Unfortunately, there is no documentation available mapping the Microsoft resources to the Resource URIs for different APIs.
Below are the details of the most common Microsoft APIs exposed on Microsoft Entra ID, along with the other details to generate an access token to those resources.
To Identify for remaining resources, please follow the below steps :
1. Login into Microsoft Entra ID: https://portal.azure.com/#view/Microsoft_AAD_IAM/ActiveDirectoryMenuBlade/~/Overview and click on Enterprise Applications.
2. Filter on Application Type = "Microsoft Applications"
3. Search for your Microsoft Resource and get the Application ID and Resource URI details :