Updated:
I have tried with this block,working fine and tested
While app initialize , it will check whether user is authenticated or not. If he is authenticated also will check his occupation and will proceed to the concern screen. If he is not authenticated below steps will allowed
step 1: User need to register
( if success Sign up VA will open, Reg VA will invisible, details will store in firebase DB and the occupation will store in tinyDB)
Step2: User need to sign up with email and pwd.
step3: User need to sign in
step4: Next screen will open as per the input data given in occupation
Simple