Android Firebase - 12 - How Read & Write Data Using Model Class (POJO) Object on Firebase Database

how can we create a new user each time save button is pressed ?

I have one question. How does the textView update automatically without pressing the Read data button ?

Can i read multiple data from the database. (if there many childs)

i have a question please! when i retrieve data it took time more than the main thread, for example my texview is already setted and i want to update it by a value form firestore. on the screen, the update took some seconds to appear . Please Help!

Source code please