There is no “Server Client” version of ELS. It’s only client side. This means there will be a bunch of issues using it with FiveM such as the lights not being synchronised. The only way to get ELS to work is if the creator of ELS either ports it over so it works or, makes the project open source so others can port it.
Other than that, I believe the only way you can get ELS to work is to have all the clients install it locally.