What is the definition of "date placed in service" on form 8936? I purchased a used electric vehicle and am trying to deduct the charging station installed at my house.

i seem to be getting an error with lines 5 and 6.  For some reason i have to fill out all of the car details for the home charging station credit and i'm not sure why i have to fill this form out.  It's a used car and I know that i dont get the tax credit for it.  The vechicle was placed in service in Aug 2018 but i bought it used in Dec 2021.  help.  Thanks.