There are two different listing options for your NFT:
As the owner, you can choose how you would like to list your NFT. The listing options are between a reserve auction (which last anywhere from 1 to 10 days, once the reserve price has been met) or you can choose to set a "Buy it now" price, which will bypass the auction process and transfer ownership once the price has been met.
We leave that choice to you as the owner of the NFT. If you change your mind and want to change how your NFT is listed, you can do this, before a reserve auction starts.