Hi Jospoortvliet,
Sorry for the slow respons 
but i have been a busy little bee
Yes i did tripple check this specifik thing and i did remember you mention it in your youtube video.
But just to be clear in my case this would be line right?
docker run -t -d -p 127.0.0.1:9980:9980 -e “domain=data.dingit.dk” --restart always --cap-add MKNOD collabora/code
since my nextcloud server is data.dingit.dk - or should it be domain=data.dingit.dk