FlatPak Installation on SD Card

Hello, as the title indicates: I am trying to transfer all my flatpak applications to my sd card and ensure that future installations also install there. I tried to do the custom installation method but it didn’t work in the second step because there are no files and even the command [Installation: “extra”] etc does not work. Please, I really need help.

PS: I’m on Steam Deck 64 GB

You probably don’t have sudoedit installed you can just try doing that with an editor, but with superuser rights or used sudo and nano together.