REST API using MS Entra ID App

Fabric REST API does not support service principal yet, it may be the reason?

https://learn.microsoft.com/en-us/rest/api/fabric/articles/using-fabric-apis#considerations-and-limitation

In my experience, some endpoints work with service principal, and some don't at the moment.

I am able to use the List Capacities, List Workspaces, List Items and some other endpoints. Do you get success if you try to call any of those endpoints?