The answer below is of course totally correct but let me just give you a piece of extra information about this one. Younger people totally use "add" as a germanized verb. Ich adde Du addst Er/Sie/Es addet Wir adden Sie adden Ihr addet Of course formal German shouldn't be mixed up with this but if you talk to younger people or actually whoever has a little knowledge about the internet, you can totally use "add".

Bitte füge mich der Monsterwelt hinzu. Danke.