We do not have Presearch as a service on StartOS Marketplace, but we do have SearXNG which you can find in the official Start9 Registry on your server.
However, if you would like to have that Service specifically added, then it might be best to contact the Calibre Team directly and ask them to package it, and if you feel really strongly, try to convince them.
If they are willing to package the service for StartOS (or if someone else is) then it can be added to the community registry → Start9's Marketplace Strategy
Or, if you feel like jumping in and doing it yourself, you can go through our Service Packaging guides, but please be warned that these are likely to change in our upcoming releases → Start9 | Service Packaging
Be aware that we do not use Docker. Podman is how you handle containers under the hood. Keep in mind that this is very different from the linux distros you are probably used to, and it is best to read the packaging docs as suggested by Okin, rather than attempting to hack it in. If you or the Presearch team have any questions regarding packaging their service, we are happy to help!