“Buy Now” listings can be cancelled at any time up until the sale has occurred.
Once a sale has taken place, it cannot be cancelled or reversed.
How to cancel your listing:
Click onto the NFTs page
Click the “Cancel listing” button underneath your NFT
Confirm you're wanting to cancel your listing by clicking “Cancel listing”
Your wallet will prompt you to “confirm” a transaction to complete the process.
You will see a confirmation screen to confirm your listing has been cancelled.