Provision of an online marketplace for buyers and sellers of downloadable digital art images authenticated by non-fungible tokens (NFTs); Retail store services featuring virtual goods, namely, footwear, clothing, headwear, eyewear, bags, art, posters, decals, stickers, calendars, board games, toys and dolls, for use in online environments, virtual online environments, and virtual reality environments authenticated by non-fungible tokens (NFTs) for use in online virtual worlds