Installing NextCloud and Collabora in two different docker containers

I have installed Apache/PHP in a docker container and NextCloud works perfectly so far but now I am trying to integrate with Collabora and… it is a no go…
My apache config work perfectly with the let’sencrypt certificates but I do not understand at all how to install those certificates on the collabora docker…
just to clarify, the config is as follow:

  • Host with an external IP and IP seen from containers
  • Apache/PHP docker - IP - accessible thru ports 80 and 443
  • Collabora docker - IP - accessible thru ports 9980

Any help would be greatly appreciated.