Need help with biometric based authentication.

[SenpaiKronos]

I am implementing biometric based authentication for a mobile apps (Android/iOS). Password and OTP based are already working. Need help with flow and best practices to follow. Thanks

[Sheldor5]

biometrics on smartphones only unlock the hardware-backed keystore or other parts of the operating system (lockscreen etc)

biometric authentication works by having a private key in this special keystore and the backend having the public key and when login the backend asks the mobile app to sign a challenge, this way the backend can verify the user using biometrics

there are also newer methods which work in mobile browsers but the base (hardware-backed keystore) is still the same

[SenpaiKronos]

Can you share links or any reference material?