More and more apps are adopting Android 10's official biometrics API, which means they now support both fingerprint authentication and face unlock, and will adapt to your phone. The latest one to join the fray is Microsoft's One Drive.
In the app, head to Me > Settings > Passcode and toggle on Require code. After setting up your 6-digit PIN, you'll be asked whether you want to enable biometrics to speed up the authentication process. On my Pixel 4, it instantly recognized my face and that was it. I can still disable the setting or remove the passcode protection altogether.
Now, each time I open the app, the screen briefly flashes (this should be fixed hopefully) and a biometrics layer shows up. It recognizes me and all I have to do is confirm to proceed. Or I can cancel and choose to enter the PIN manually.
Left & Middle: Enabling biometrics in OneDrive. Right: Face unlock screen when I open the app.
You can now set up OneDrive to unlock with your face, if your device supports it.
Face unlock and biometric support are rolling out as part of v6.2 of OneDrive, which is available on the Play Store and APK Mirror.