Collabora Online and Seafile

I am trying to integrate Collabora Online and Seafile w/o success. I get

"Unauthorized WOPI host. Please try again later and report to your administrator if the issue persists."

It may be, I have misunderstood the manual, so I will be thankful if somebody can confirm such setup can be done with one server only for Seafile and Collabora in a docker container?

My setup:
1 server for both (Ubuntu 16.04)
Seafile domain =
Collabora domain =
Seafile 6.10 CE
Latest nginx
Latest Collabora
Let’sEncrypt certificates

I start collabora with docker run -t -p 9980:9980 -e “” -e “username=admin” -e “password=S3cRet” --restart always --cap-add MKNOD collabora/code

Thanks in advance for your support