If you wish to cancel or change a purchase you made in the ID.me Shop, it's best to cancel the purchase with the retailer / partner website, then make a new purchase via a link in the ID.me Shop. This will ensure you earn Cash Back when your purchase is eligible.
While you may contact the retailer directly to make changes to your purchase (for example, to change your payment method or add an item), such changes are likely to void your ID.me Shop purchase and result in no Cash Back.