So you freed Lanilor, then entered the catacombs, and he approached, giving you the teleporter?

If you open the skill selection menu on the skillbar, are there now icons on the right column (with the special move), where you can drop, use or drop and use the teleporter pyramid?

It should be in the miscellaneous section of the inventory after Lanilor gives it to you.

Could your character have been over-encumbered? (particularly if you had been looting by placing items directly into an open container in your character's inventory) If your character could still move after speaking to Lanilor, this would not have been the issue.