Your quick connect is likely regulated low pressure propane, the same pressure that is used inside a grill. This means the grill's regulator needs to be removed and a quick connect plug added.
There are you tube videos, 'how tos' to do this for specific models of coleman grills.
https://www.youtube.com/watch?v=eQjjCwknAikThis does not work for a coleman propane stove since the stove's operating pressure is 15 psi, ie regulated high pressure, don't confuse regulated pressure with container pressure which varies widely based on temperature.
