It was already described e.g. here KDE devs have been quietly working on Plasma Keyboard! - #3 by alexp11223
Also this comment may be useful Onscreen Keyboard / Virtual Keyboard (#21) · Issues · Teams / KDE Goals / We care about your Input · GitLab
It was already described e.g. here KDE devs have been quietly working on Plasma Keyboard! - #3 by alexp11223
Also this comment may be useful Onscreen Keyboard / Virtual Keyboard (#21) · Issues · Teams / KDE Goals / We care about your Input · GitLab