But what happens if you forget the password? or wish to return it to the default?
In that case removing the app and reinstalling it would probably wont work for you.
So what can you do?
these is what you need to do in-order to reset the password:
open up home directory and change the view to show hidden files > now go to .config > qBittorrent > open qBittorrent.conf with your favorite text editor and look for the line where it says:
delete whatever the password is equal to (zzzz's in my example), save and exit.
Make sure you do it while qBittorrent is closed otherwise it'll just recreate the same document automatically to overwrite your overwriting.