You need a coin door with a hole for it like this :
https://www.pinballlife.com/williamsbally-coin-door.html
Then a 110volt AC easiest and cheapest. MARS/MEI off of Ebay. Rebuilt for ones and fives. 2400 series. Then get one of these :
https://na.suzohapp.com/products/bill_validators/42-7057-00
Plug cord into service outlet. Two wires to to one of the coin switches, one wire on each wire of the coin switch.
LTG : )