Urgoz's Warren. No teleport, GG?

I'm at the second room, the one with the bridge and a teleport beacon on the right side. However, the teleport isn't working, and my friend told me if no necro nor assassin have teleport skills in order to teleport themselves up there and open the gate, that's over. Is it really so?

Correct. The Teleport u see is for someone to teleport from bridge to ground level.