Is it not powered thru an inverter? Should be...this a new trailer, or new-to-you? Is there an inverter somewhere in the basement area? If not, a cold and closed fridge will hold temps without power for about 4-5 hours, tnen hookups or generator.
First thing, check for an inverter somewhere that only powers the fridge...
2016 Tiffin 40 QBH
2015 38RSSA, traded
2005 TK3 #1869, 10 yrs of memories,
2017 F450 KR--one more Ford is it
2009 F450 4x4-died; 2010 F450-retired