Realize Google AppInvite
by Google
manual - link.
Start Invite Activity
and get next in the LogCat:
E/AppInvit
In firebase console under Project Settings find "Certificate Fingerprints (SHA-1)" part and from the help icon you will be directed to https://developers.google.com/android/guides/client-auth and enter generated SHA1 keys for both release and debug certificate fingerprints. Then resultCode 3 will gone and you will send the invitation.