setting default magnet app in firefox, but i cant navigate to where the qbitorrent binary file is

ive seen a lot of answers about opening magnet links in firefox. a lot of them tell you to go to about:config and change network protocol handler …….. to false etc. ive done that.

now i get an option to choose which application to open the magnet link with. Now here is where my problem lies. i Have firefox installed as a snap package and qbittorrent as a flatpak. when prompted,i try to choose from firefox which app to use for magnet links. the thing is the executable for qbittorrent lies in my /var/lib/flatpak/apps folder. when i try this from the prompt window within firefox it tells me i dont have permission to open /var
What should i do????