If an RV has a quick connect that port is coming from your propane tank, which already has a regulator. If you use the hose that comes with the griddle there is also a regulator built into it. Double regulators means low gas flow and the griddle won’t stay lit.

You need to buy a hose with a quick connect but no regulator and use that instead of the included hose.

This one works. https://www.amazon.com/gp/product/B08YFCYBVJ/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1