BiometricPrompt CallBack Not triggering

[fatsolow88]

I try to implement either the Gradle way or the source code way, I realized none of the callbacks are working so it doesn't create any attestation object after I verified it with my fingerprint. Not too sure which part did I messed up with.

Stuck at the part for
"6. Obtain user consent for creating a new credential"

Update

Once I commented out the "exchanger" which is supposed to wait for the result of the attestationobject, the callback is working again, but no way to pass back the object through the method