Current implementation of PopSigner.Jwt although it uses JWSSigner from Nimbus,
it doesn't provide the ability to suspend signing in order to allow the user to authorize with biometrics or PIN the use of the Android Keystore.

The approach is explained here

• Allow caller to provide a lamda for authorize the signature. This lamda should be part of the PopSigner.Jwt
• Change JwtProofBuilder to suspend signature, execute the lamda and then resume signing.