I have 2 source codes - Need to merge them into a single working app (Music Streaming Android Java)

Project duration - 0.5h - 1h Needs to be done by - 2 hours from now The original app has all of the features coded but is connected to the wrong Firebase account. as such, it crashes when you try to upload a song (admin) or to play a song (client). My own app (it was built by me through manually writing the exact same code as in the original app and making adjustments where errors were found) doesn't have all of the features coded (it's only 70% complete) but it's connected to the right Firebase account and the features currently installed on it all work. The "original" app is just a code from a Youtube Tutorial video. Each "app" is actually two separate apps - The Client side, and the Admin side. meaning literally, we're talking about 4 apps here. What I need help in is getting these two (four) source codes, and matching them so that I have one (two) apps that are connected to the right Firebase account, have all the features and they all work properly. Basically, it's a mix and match.