Comment by maqp

Well not quite :) Wrt what upper post said:

It used to be the case you could only exchange keys in person, but X25519 was introduced in 2016, and it was bumped to X448 in 2019. You can of course still exchange PSKs as it's currently the only post-quantum key exchange it can offer. QR-codes are not used, instead, imported strings are split into small segments that are typed manually. The program then does what it can do, to help the user identify typos.