I can't see/find the oil drain cap on 1999 Toyota 4Runner

Need to drain oil after putting too much in and cannot see/find oil cap under truck, is there a plate or something I need to remove to get to it and the oil filter? Any pics?

Asked by for the 1999 Toyota 4Runner
Their is a black protective cover under the engine. Their is a recessed hole in the center of it, between the wheels. The drain plug is there.