Probably https://cubiclenate.com/2018/04/16/kde-connect-remote-keyboard/ (or gsconnect).
“Twitter! I need help. I want to use my Android phone as a keyboard on my TV PC (Kubuntu), what are my options?”
beko.famkos.net
User Slice of beko
Holy crap kde connect can do it, had no idea. Perfection, cheers!
I think so but I only used the touchpad as mouse so far. Mileage may vary.
I’m doing it now, it works great 😀
community.kde.org/KDEConnect for the upstream documentation, just in case