As mods are version specific, they will only work on the version of the game they were created for and not any others. A mod created for Forge 1.16.5 will only work on Forge version 1.16.5. If you try to install it on a 1.20.4 server, it either won’t load at all or the server will crash on startup.
Mod dependencies provide a solution for sharing mod contents across multiple other mods. Some mods require you to install other mods in order to run correctly. These are often either specified in the console when trying to start the server up without them, on the mod page itself or could also be found from the Relations tab at the top of the mod's Curseforge page.
How To Install Mods using the Mods Tab?
- Head over to the Game Panel and stop your server.
- Navigate to the Addons → Mods tab and find the mods you'd like to install.

- Start your server and take a look at the server's console to make sure the mod(s) started up correctly.

How To Install Mods Manually?
- Download the mods you'd like to add to the server from a website like CurseForge or Modrinth.
- Head over to the Game Panel and stop your server.
- Navigate to the Files tab and into the
modsfolder. Upload the downloaded mods there.

- Start up your server and make sure your mod loads up correctly.

- Download the dependency mod and upload it to the
modsfolder like previously done with the previous mods.
