On screen keyboard for Zhuyin/Bopomofo or Cangjie

[H-Cl]

Hi

I'm looking for an on screen keyboard for the input of traditional Chinese characters.
I installed ibus and it seems to work, but as I understand, a keyboard with a special labeling is needed to use it.
There are only very few keyboards that I can get in Germany and I don't know if they can be used for for traditional chinese characters with those input methods at all, so an on screen keyboard would be the best solution I think.

I tried Kvkbd but I can't manage to display any other characters than latin with it.
Is there a way to change the labeling or is there another on screen keyboard that I could use?

謝謝