the 2019 ES300H makes noise when off and keys not nearby?
I just bought the Lexus 2019 ES300h - the car is making a humming noise in
the garage - checked - car is off and my keys are inside?
Could be a feature turned on that keeps a pump on for recirculating the coolant. Have a look in your manual perhaps you pressed a button on the climate control that has that feature. If no luck give the dealer a call or bring it in. I am sure it's still under warranty. Good Luck!
It also could just be the fuel pump still circulating s bit, pretty normal for most cars.