Sorry if this is an obvious question.
You don't mention a pilot flame for the refrigerator.
Is the pilot flame going??
If not first ensure that 12V and 120V switches are turned off.
Turn the propane select knob to ON. Depress/press the knob down.
This will start the propane flow. If clicking is heard this is the piezo sparker trying to light the propane pilot. If no clicking is heard then light the pilot with a BBQ lighter. Continue holding the knob in for about 15 seconds. When you release the knob the pilot should remain lit. If it doesn't relight the pilot and hold another 15 seconds. (Pressing the propane knob IN to begin pilot lighting sequence is a safety sequence used to turn off the propane if the pilot light gets extinguished)
After the pilot is going the refrigerator should begin getting cooler.
Please note the trailer/RV should be be relatively level for good operation of the refrigerator.
I can just see the pilot going on my refrigerator. Faint blue light thru a tiny gap in the chimney assembly. Very easy to miss . . . The chimney will get hot (don't burn yourself