Bip39 Ian Coleman. Now, at the next level we use these getting and change critical bunch to create unique non-public keys. Use the above produce private keys and chain code and go them to the above outlined functionality kchild = kpar + hash(Kpar, cpar, i) to crank out person keys. https://free-bookmarking.com/story19050511/bip-39-https-linktr-ee-bip39-getting-my-bip39-passphrase-to-work