OK Thanks Nils, I will give it a go!
On this page (Docker) there is a link to the docker installation guide which returns a 404:
https://hub.docker.com/r/openrouteservice/docker/README.md
I thought I would point that out. Otherwise I have found instructions here
https://hub.docker.com/r/openrouteservice/openrouteservice
https://hub.docker.com/r/giscience/openrouteservice
https://github.com/GIScience/openrouteservice/tree/main/docker
If there are any key sources of instructions please let me know. Thanks