NFTs are digital art but also involve cryptocurrency. IRS classifies investing in collectibles in retirement accounts as prohibited transaction. Since legal and tax experts are still working out the details if NFTs are considered a collectible or property, it is best to avoid buying or trading NFTs in retirement accounts. If you want to invest crypto in IRAs, it is best to go with reputed providers like Alto CryptoIRA, Rocket Dollar or Bitcoin IRA who can provide appropriate guidance and compliance