Bip39 Checksum. Now, at the following amount we use these receiving and change essential bunch to deliver specific non-public keys. Use the above create personal keys and chain code and go them to the above mentioned pointed out purpose kchild = kpar + hash(Kpar, cpar, i) to deliver individual keys. https://socialmediatotal.com/story4569374/bip39-mnemonic-https-linktr-ee-bip39-getting-my-bip39-passphrase-to-work