Welcome, @LukeStarlord349, and I'm sorry to see you've hit this issue. Could you please double check that you created the allow-postgres14-upgrade file as described in step 8 of https://docs.getodk.org/central-install-digital-ocean/#getting-and-setting-up-central?
That file is intended to signify that it's ok to upgrade postgres. It makes the most sense in the case of an existing install upgrading to postgres14 but is also needed for new installations.
The upgrade image is pulled from Dockerhub where the 9.6-to-14 image still exists: https://hub.docker.com/layers/tianon/postgres-upgrade/9.6-to-14/
When you have a chance, we'd love to know more about what you're planning to use ODK for in the introductions thread.