You are allowed to retract a bid for very few reasons.
Be aware that the seller can report a buyer for bid retraction if they believe the reason given is invalid, and if it happens too often eBay can put sanctions on your account.
Many sellers block those who have retracted a bid on their item and some sellers check bid retraction history and cancel the bid if the retraction number is too high.
https://www.ebay.co.uk/help/policies/rules-policies-buyers/invalid-bid-retraction-policy?id=4227&st=...
@eileenbell1953
