3.5 inch hole saw: https://www.amazon.com/gp/aw/d/B082SNGK7K

Siding mounting block: https://www.amazon.com/gp/aw/d/B001B15818

RV cord hatch: https://www.amazon.com/gp/aw/d/B017KWL4IM

You can Mount the charger on a piece of wood, but if you want a neat/OEM installation, you can buy a “flat siding mounting block” at your local home supply. It’s a piece of contoured plastic that fits over the vinyl siding like this:

https://www.amazon.com/Builders-Edge-130110008123-Surface-Block/dp/B001B15818/ref=mp_s_a_1_10_mod_primary_new?crid=3MXT11GFGO0NE&keywords=flat+siding+block&qid=1661524265&sbo=RZvfv%2F%2FHxDF%2BO5021pAnSA%3D%3D&sprefix=flat+siding+%2Caps%2C75&sr=8-10

And consider installing a charger dock/cord reel or hook. I have one of these and it’s perfect:

https://www.amazon.com/LECTRON-Charger-Holster-Combination-Connector/dp/B07FC9M4YF/ref=mp_s_a_1_3?crid=159HB2VL53C9N&keywords=ev+charger+holder&qid=1661524428&sprefix=ev+charger+holder%2Caps%2C70&sr=8-3