Addon installing without subscribing

Hey I copied about 200 GMod addons from my friends hard drive and they don’t seem to show in online mode. I think this is because I haven’t subscribed to them, is there any way I could work around this?

No. Your installed addons are not supposed to be available on someone elses server.

When I say online mode I mean my steam account. They will not show up in a single player game with steam online but on steam offline mode it will.

Well, then subscription is the exact reason why they won’t show up. Or you can drop them into addons/gma/ and they should load regardless.