Groovahloic

Hello guys Im new to the whole server thing so please be kind with any replies, is there any sort of help with installing mods for Valheim, at the moment we have got r2modman running with most mods, but there are 3 others that need to be installed server side for them too work. I noticed that in the control panel there is a mod tab which already shows Valheim+ (not installed and dont want it) but I just can't work out how to install any other mods that need to be server side, do I need to make a named folder anywhere and upload mods to that? A nice A-Z would be very helpful. Also all the server files are not on my computer they are on my friends I have just got access to the Tcadmin control panel Many thanks