KeePassXC available in stretch-backports

sudo apt -y purge keepass* && sudo apt install keepassxc -yt stretch-backports

You’re welcome.

Full instruction for using backports:

Install Additional Software Safely

That would depend on whether we think KeePassXC is the best password manager there is in Debian. For a more detailed discussion there is a thread for this topic somewhere on the dev subforum.

Certainly.