Playit installed previously but deleted, refuses to install again even after fully restarting/reinstalling Debian

Heya. I’m accessing my server locally via CasaOS. Right now I have to manually start playit.gg via tmux each time the server starts up, since I installed it using the alternate method. But I would rather it be automatic without relying on tmux: the preferred method of installation. But this doesn’t work…

Here is what pops up when I execute the first command:

…How do I resolve the issue regarding the “no valid OpenPGP data found” error? Or alternatively, how can I set tmux to automatically run playit whenever it isn’t?