If you have committed to purchase an item, then you should pay for it.
You can ask the seller to cancel, but the seller does not have to agree to that.
If the seller does not cancel and you do not pay, the seller may file an unpaid item case against you. One case alone may not affect your account, but if you have two such cases within the last year, many sellers may automatically block you from bidding or making a purchase.
https://www.ebay.com/help/buying/paying-items/paying-items?id=4009
