Solved
First, I could not open the virtual keyboard on IPad Pro 2018 (iOS 12.1). I solved this issue by downloading the TestFlight version. However, some keys are out of screen (as can be seen in the screenshot) and can therefore not be pressed.
Files:
712448A5-2D27-4...
The same problem 
Please try the version in TestFlight:
https://testflight.apple.co...
Comments have been locked on this page!