For a student based app job alerts and blood bank app

For a student based app like job alerts blood bank and other features which data base backend is better currently i am using firebase realtime database but if I use that I think if anyone do reverse engineering like extraction of apk and he can see the firebase url and hack the app what I am thinking is to make secureapp how if anyone can have Idea

then go with google sheet. Use apps script, along with authentication. Sheet 1 should contain user name and password. IF it matches then look for the blood bank of jobs from sheet 2

try this code. I always recom his code writen by @TimAi2

Firebase is very secure if you know how to configure and use it.

i think if the firebase url can be seen in app extraction if they got the link all the data can be seen using that link itself i think its not safe

Read a little about what the rules and tokens are.

are you saying that if some one extract the app and got the firebase url and he cannot get the data by adding .json at the end ?