Since Xbox/PS players can now join PC lobbies, you should be allowed to use keyboard and mouse on said devices! I use KB/M for games like Sea of thieves on Xbox, so
playstation now keyboard mouse off 76% - wentylacje.pl
How to Use a Keyboard and Mouse on a PS4
PLAYSTATION NOW MOUSE+KEYBOARD :: Off Topic
Sony PlayStation Now Review | PCMag
Best PS5 keyboard and mouse combo 2023 (Budget, High-End, Mechanical)