Humming sound

It's a 2021 4runner TRD ORP with KDSS.

parked the car this morning around 11am. went in the garage to get something and I hear a humming noise and it took me couple of minutes to figure out that it was coming from the area on the driver side rear wheel well. I also can hear it in and around the spare wheel. not sure what it is.

I tried uploading couple of videos, but the file extension is not supported here. Anyone know what it could be?

 

Straight out of the owners manual.... page 8 in mine
Noise from under vehicle after turning off the engine
Approximately five hours after the engine is turned off, you may hear sound coming from under the vehicle for several minutes. This is the sound of a fuel evaporation leakage check and, it does not indicate a malfunction.

 

Perfect. Thanks for the quick response.