Install Fabric Mods on a Server

Download the mods that you want to install. For compatibility, they need to be the same Minecraft version as your server. For example, if your server is 1.12.2, the mod must also be 1.12.2.
Log into your server SFTP.
Navigate to the SFTP folder for the game on your server that you want to work on.
Upload your mods (one at a time, repeating these instructions as necessary) into the mods folders. The mod’s installation instructions should specify the folder(s) to place them into if they are different.
Log into Command Center. From the server list, find the server you want to install mods to and click the Manage button on the right.
When you’re ready, restart your server.
If your server fails to start, or crashes after adding a mod, you will need to talk to the mod author or open a support ticket. Sometimes we can help resolve simple issues, but many times with mods, the issue is a bug in the code that has to be fixed. In the mean time, remove the mod and repeat the above instructions for any more mods that you might have.