This is a quick repair of a Colzar 15" beverage fridge suffering the E3 error (https://smile.amazon.com/Colzer-Beverage-Refrigerator-Counter-Freestanding/dp/B09C644LHW). I couldn't find anything that looked like a parts diagram, any parts, or get any response back from the manufacturer on what to do to fix it. Sorry, I didn't actually make a parts diagram

You need a new 10K thermistor, https://smile.amazon.com/dp/B086YD9L28 should fix it. E3 seems to be the sensor on the coils, I think. So that was the red one in my case, your mileage may vary, but it's probably the same sensor on both. Splice in the new one(s) and you should be back in business. I'd recommend heat-shrinking them because of the location to the coils.

Also, bonus tip on how to take out the trays at 01:05 ... don't just lift, lift and GENTLY bend outward from the rail and hold them on the sides.