You may want to try installing using a deb package, see package install on: https://www.collaboraoffice.com/code/
Unfortunately you are on your own after the install to get it setup correctly. The rest of steps are not explained but can be determined from the Docker install instructions. The configuration file is /etc/loolwsd/loolwsd.xml.
- Need to set loolwsd to listen to localhost:9980 in loolwsd.xml.
- Make or install certificates for your collabora server and enter their location paths in loolwsd.xml in the ssl section. It is critical you get this part correct for each part of the certification: the certificate, the chain and the key.
- In loolwsd.xml set domain to location of ownCloud using \ in front of the “.” in your domain name.
Then set up Apache according to link above.