Creating a white-label NFT marketplace is not an easy task. Generally, it takes up to several weeks depending upon the requirements & customizations needed for the marketplace.
Yet, Bitdeal one of the leading NFT Development Company is offering White Lable NFT Marketplace within 48 hours. They just released this update to their NFT Development page recently.
They are in this industry for several years, and now they have decided to move further. Also, they are offering demos for this update. Check out their official site for more information.