2021 is the year that belongs to NFTs. As non-fungible tokens, NFTs are unique digital identifiers that record ownership of digital assets. In supporting the Metaverse economy, NFT has been placed high hopes by the market. So, with the fire of the metaverse, NFT also ushered in the spring. In the first half of 2021, the overall market value of NFTs increased by nearly 310 times compared with 2018. As of August this year, the transaction volume of OpenSea, the world's largest NFT trading ...