In older versions of the software, there is no OpenScape keyboard layout. To use the OS, you need to make changes in TAPRO, usually from 50 to 60. Buttons from 1 to 8 on the base unit already have functions, so buttons from 9 onwards are used for functional purposes.
For example
CHA-TAPRO:,56,OPENST40,,,,,,,,,VACANT,VACANT,VACANT,VACANT,VACANT,VACANT,,,,,,,,,,,,,,,,,,,"OpenStage - OS40";