I recommend using the dockerized version, docker compose to be more specific: https://docs.gitlab.com/install/docker/installation/#install-gitlab-by-using-docker-compose

This has nginx already in the GITLAB_OMNIBUS_CONFIG.

I am not aware of any "specific" configuration either, as mention, the WebSockets might be something extra the fiddle with. But if you put a reverse proxy in front of gitlab, disable the http_to_https redirect in omnibus config if the reverse proxy is already handling that