Power Failure Alarm, Upgrade 120dB Power Outage Alarm for Freezer, Power Outage Monitor with LED Indicator & Extender Socket, GFCI Circuit Failed Detector for Home, Garage, Basement

A power loss alarm would work. They also make versions that can alert you via wireless.https://www.amazon.com/Failure-Indicator-Extender-Detector-Basement/dp/B0DM5S5VK8 I also recommend these or a GFCI with an audible trip alarm for fridges and freezers that you don't go into very often.