The Apollo 17 ascent stage lifts off from the Taurus-Littrow Valley at 2254 UTC, 14 December 1972. The takeoff was captured by a television camera which had been left on the surface of the Moon.
Apollo 17 LM Ascent Stage liftoff at Taurus-Littrow, 1654+36 CST 14 December 1972
so where are the fuel tanks and rocket engine – all part of the descent vehicle?
The descent stage and ascent stage each have their own engine and fuel system.