In my case, where I really want it to be safe to the max, I SSH into my server with PuTTY, where it first authenticates with the ppk, then asks me for my password and my 2FA code. FileZilla on the other hand, if I choose key file, it says that further authentication is required, but if I choose Interactive it asks for my public key. The way around this is to first select Key file and then Interactive, as it caches the key apparently? But it is really annoying to do every time.
I do not need to use FileZilla specifically, I only need a GUI SFTP program.
Thanks,
Matic