For sale: kids scooter, used but fully functional. LEDs in the wheels are not as bright as new. The headlight on the handlebar works perfectly, on replaceable batteries.
Never pay down a deposit in a bank account until you have met the seller, seen signed a purchase agreement.
No serious private advertisers ask for a down payment before you meet.
Receiving an email with an in-scanned ID does not mean that you have identified the sender. You do this on the spot, when you sign a purchase agreement.