SFTPpage. You can use the Quickconnect in the bar.
/7daysserverfolder. In here you will create a new folder with the word Mods as you see here. (Note: If you have never installed mods/modlets on your own client seek a guide on how to before attempting an install to a server.) Now that you have a Mods folder, this is where you will be able to place all Mods so long as they work on your client they should work here too. If not reach out, and we can assist.