Can the on-screen keyboard be placed on the side of the app?

Question

Android

On a smartphone, I use MessagEase Keyboard for input . For the question, it doesn’t matter how it works, the main thing is that it requires little space and, in its minimal form, fits compactly under one thumb.
In portrait mode, there are no questions about ergonomics:

In landscape mode, the keyboard itself occupies a quarter of the screen, but another quarter (highlighted in red) does not perceive the touch:

Naturally, there is a desire to position the keyboard on the side (I photoshopped an approximately ideal version):

Well, or at least like this ( the keyboard itself supports mode without a numeric keypad):

Is this even possible in android? Can an existing keyboard be placed on the side? If not, is it possible to at least make your own keyboard with support for such an arrangement (a quick look at the Android API did not reveal anything similar)?
Thank you!