Nostalrius Begins - Quality wow vanilla realm (1.12)

Hello. I just started as Warlock and my summon dont want to attack :p Its my first time in WoW so maybe i do something wrong but when i click "attack" button on summon skillbar nothing happend... he can only use fireball but no any other attack :/

Hi fellow warlock! The imp's only attack is a fireball. It should auto-cast it when you activate the Attack button.
Other pets have melee attacks.