How to install on a server with an existing Nginx?

I would like to install Gitlab on an Ubuntu 18.04 server with an existing Nginx webserver. I do not want to use the Nginx server bundled with the Gitlab Omnibus package, because I am afraid it will break my existing installation.

Is it possible to do this while still using 'apt-get install gitlab-ee`? If so, how? If not, what are the alternatives?