About firebase DB - java extensions

Hi
how to check value from firebase under specific project bucket?
how to set value to firebase under specific project bucket?
also, how to set the real time DB URL?
For example:

my project bucket is “passwords”
my tag is “myName”
value “Pass12”

I mean how to write this in java code, for use in my extension.

Please Ask in MIT App inventor community . Kodular Dosen’t Allow Extension Devlopment Topics