Flatpak recently got a method of preinstalling flatpaks.
A flatpak cannot install a snap on your system. Apt can install a snap because when apt installs and updates packages, it can also run scripts as root. That’s insecure and potentially dangerous, so flatpak doesn’t have that ability.





I went for the simplest option
Found it very simple. Avoided the tedious setup of samba and samba had weird reliability issues for me when copying large files. Took a bit to learn how ssh works, but very much so worth it.