I've been using the app "Fingerprint Quick Action" in order to turn of the screen via fingerprint sensor.
Link to said app:
Now with Android Pie it has stopped working. The devolper acknowledged that by saying:
"Android 9 does not allow listening fingerprints in background, so unable to use this app."
So my question is if there's another app or workaround in order to achieve it or am I out of luck?