Bip39 generator python https://www.empowher.com/user/4550298 Checksum generation: A checksum is generated from this entropy working with SHA-256 hashing, which can help validate the mnemonic's integrity afterwards. For words that only have 3 letters, there is no 4th letter. As an example With all the word “add”, there isn't any extra letters https://setbookmarks.com/story20043970/unknown-bip39-wordlist-the-5-second-trick-for-bip39-compatible-wallet-https-dzen-ru-bip39-phrase-com