Bip39 ozon https://www.empowher.com/user/4550298 D'CENT Biometric Wallet - A hardware wallet which has a biometric authentication feature, supporting BIP39 seed phrases and offering an added layer of protection. For words that only have 3 letters, there is absolutely no 4th letter. For example Using the word “incorporate”, there aren't any more https://bookmarksystem.com/story19889244/bip85-vs-bip39-bip39-github-an-overview-https-dzen-ru-bip39-phrase-com