Hi guys.
I've follow the instructions on https://nextcloud.com/collaboraonline/ to integrate Collabora Online with Nextcloud, using LinuxServer's Nextcloud & LetsEncrpyt containers as the basis.
Had to follow https://icewind.nl/entry/collabora-online/ for NGINX instructions (configured on the LetsEncrypt container, adding "office" to the list of my subdomains).
The only things I had to change from the instructions in the links is:
replacing "127.0.0.1" to my unRAID IP on
How to setup collabora online with Nextcloud behind reverse proxy, 3 steps:
-Letsencrypt nginx conf file
-Collabora docker configuration
-Installing collabora app under admin account in nextcloud web page
The key is to use another domain name for the collabora docker and nginx conf file. Meaning, if you have used cloud.* in letsencrypt nextcloud.subdomain.conf, then you gonna have to use office.* in you server directive of the collabora.subdomain.conf.