There's currently a discussion happening between Mobian developers on whether to stick with phosh-osk-stub as a keyboard or switch back to squeekboard (which was replaced after having been removed from Debian testing for a while).
If you feel one option is a lot better for you than the other, let us know at 
GitLab
RFC: phosh-core: Make phosh-osk-stub the default OSK (!38) · Merge requests · Debian On Mobile / meta-phosh · GitLab
The problems with key input of electron apps are unfixed since many years. Let's pick an OSK that hopefully can print letters for all the keys on a...