Unity firebase azure active directory integration

Hi
I’ve already set up and project in firebase for authentication.
The app is made in Unity, so I’ve installed firebase sdk for Unity.
I’ve also set up Azure active directory and and my own api.
Now I need to get access to my api via the mobile app. I’m trying to get access token using custom scope.
I need someone who has done this before and can show me best way to do it.
You’ll need to connect via remote desktop and walk me through the process.
Please only bid on this if you have plenty of experience in this area.
Thanks