Bip39 tool github https://collinmmss433.lucialpiazzale.com/from-concept-to-fact-generating-bitcoin-addresses-with-bip39 The last move of BIP-39 is producing the particular binary seed that is then employed to be a master essential in BIP-32 deterministic wallet or using other methods. For words that only have three letters, there isn't a 4th letter. Such as with the word “insert”, https://wiishlist.com/story20779564/bip39-to-binary-helping-the-others-realize-the-advantages-of-bip39-passphrase-https-cutt-ly-uryc5rw7