The teleport-enabled weapons are a new feature added in DDNet version 11.3 released in August 2018.
Weapons need to be collected and activated with a teleporter weapon on tile.
You can then teleport with Pistol and Grenade by hitting hook/unhook (collision) tiles with a teleporter gun block tile on top in the front layer.
Laser teleports you if the last tile it bounced off was a teleporter gun block tile or if it didn't hit a collision tile at all.
The orange tile cancels movement after teleporting while the blue tile preserves movement. Note that unlike normal teleporters, hook is always preserved when teleporting with a teleport-enabled weapon.
You can use the switch layer with a teleporter gun block tile to allow only specific weapons to teleport.
Modify the delay value to select the desired weapon: