On ours, the fitting is located well to the front, just behind the landing gear, and about a foot back under the trailer. You almost have to get down real low and look up at it, but then it is real obvious. The black arrow is pointed right at the gas quick connect fitting.
__________________
'11 Cougar 326MKS loaded with mods
'12 Ford F250 SuperCab 6.7 PowerStroke Diesel
Amateur Radio: KD2IAT (146.520)
GMRS: WQPG808 (462.675 TPL 141.3)