AuthorizationFailed when trying to use Capacities-Suspend API endpoint

[latearrival]

Hey guys. I'm new to PBI (2 days in!) and I need some help using the API to suspend my PBI Embedded A1 Capacity. I want to do this as a back-end function from a web server (no user interaction). I've been testing the POSTs below with Postman....

When I do a POST to Suspend Capacity with this URL...

https://management.azure.com/subscriptions/{subscriptionId}/resourceGroups/{resourceGroupName}/providers/Microsoft.PowerBIDedicated/capacities/{dedicatedCapacityName}/suspend?api-version=2017-10-01

... I get this error message:

"error": "invalid_grant",
"error_description": "AADSTS65001: The user or administrator has not consented to use the application with ID 'bla bla bla bla'.... Send an interactive authorization request for this user and resource".

I got that error message when I used the Access Token I got from POSTing to:

https://login.microsoftonline.com/common/oauth2/token with grant_type = password.  I used the username and password of the Global Admin.

I then tried getting the Access Token, by POSTing to:

https://login.microsoftonline.com/{tenant ID}/oauth2/token with grant_type = client_credentials. I used the Client Secret of my (only) registered app.

This time, the POST to Suspend Capacity returned this error message:

 "error": {
"code": "AuthorizationFailed",
"message": "The client '80d81297-xxxxxxxxxxx' with object id '80d81297-xxxxxxxxxxx' does not have authorization to perform action 'Microsoft.PowerBIDedicated/capacities/suspend/action' over scope '/subscriptions/3ae6d438-3b19-41ee-acf6-9c4cec5c33ce/resourceGroups/CIOPulse/providers/Microsoft.PowerBIDedicated/capacities/ciopulsepowerbi' or the scope is invalid. If access was recently granted, please refresh your credentials."
}

(I have no idea what that object id is in the error message. I don't recognise it at all).

What do I need to do here?  As you can tell, I have no idea what I'm doing and I'm just mucking around trying stuff. So any help would be much appreciated. Cheers!

[latearrival · Accepted solution]

OK, I solved this by:

- Going into my Power BI Embedded Capacity.

- Clicking Access control (IAM).

- Assigning the Role, 'Owner', to my registered application.

If there's a better way, please let me know.