The
shows how to make a keyboard out of a Layout and buttons as a small part of the tutorial.
Perhaps that tutorial will help you with part of your project. Yes, you can use this type of 'keyboard' to enter data into a textbox, however you can enter data into a label as well and if you use your own keyboard you possibly can eliminate the need for the textbox when using your own keyboard?
You probably can close the default keyboard with AI, I am not sure you can replace it automatically.
Regards,
Steve