With all the talk about DEF failure, some due to crossed DEF tank heating lines, I tried to access the tank and look but I can't see how to get to the tank. On my 2021, I know it is under the driver steps but it is behind a large fiberglass panel, the one with the steps. I can't see any screws or fasteners. I climbed under the chassis but only see a large protection plate, no fasteners. Any clue?