Hello @LadyFitzgerald
go to
/home/yourusername/.config/BraveSoftware/brave-browser/Default
then look for file called Login Data
but the issue that this file is encrypted using your old username account
so i do not think that it will work
but give it a try
another way that i am not sure if it will work or not
copy your brave-browser folder from your old drive to any location you like then
that you start brave using flags --user-data-dir=the new location that you copied our folder too (use brave-browser folder)
so for example it could be something like that /home/username/Downloads/brave-browser
brave-browser-stable --user-data-dir=/home/unknown/Downloads/Brave-Browser/
the brave-browser-stable are in the /usr/bin folder
and see if it show up your old profile or not
if it did then see if you can go to brave://settings/passwords and export the password from there
hope that help and have a nice day 