Winterass

Hello everyone, i have a question i want to programm a Java Forge mod for the Minecraft version 1.18.1 and i dont know how to do that. I have experience in Java developement for Minecraft, but i want to programm a mod where the user does not have to install a mod but it is only on the server, e.g. as with bukkit etc. how do I go about it or what do I have to do so that it is only used on the server side? Lg Timo