Postman Error "message": "Insufficient privileges to complete the operation.",

Greetings all, I have a registered app that has all the read access I require against the Microsoft Graph Rest APIs. I have the tenant, application ids and secret key.
i have done the get app-only access token and the token is populated in postman. When I get users i get the following error "Insufficient privileges to complete the operation.

All the access has been granted by the domain admins (read)
I want to start by calling this rest api https://graph.microsoft.com/v1.0/users

My end goal if possible is to do the following. I want to use postman to create complex GET requests so i can use them in PowerBi. As an example. I want to get all the Microsoft Team groups, all the apps installed in the groups and the users using them. Can i use Postman and use it within PowerBi??