could someone send the link to me thanks

No there isnt.

There have been multiplayer/co-op mods for Bethesda games but all are defunct and crap.

To make a multiplayer mod is beyond the abilities of most modders. This is because it requires editing the base code of the game, something not done via the CK.

Next, for any kind of multiplayer to work, histocially speaking, everyone onboard needs to "run" the same version, including mods. If you have a favorite mod and nobody else does, you don't get to play with them. Finally, all previous versions of multiplayer gamesas games are extremely limited in scope, usually allowing only a handful of people in-game at once, and none have passed beyond late Alpha stage.

Even if there was a mutliplayer FO3 mod, you're going to be dissapointed with it.