I went to a big store and tried alot off cases. I found only two in which the jolla + tohkbd fits:

https://de.hama.com/00087742/hama-ha...schwarz-gr-xxl

https://de.hama.com/00087743/hama-ha...o-braun-gr-xxl

I use the first one. It fits barely so its a bit hard to pull out.

The second one has its own magnet so it can be problematic with the tohkbd magnets ^^