I took the index in the words, converted the variety to binary, added three zeros, calculated the sha256 digest, took the very first Element of the hexadecimal to transform it to binary, included a few zeros for the 8 digits of your binary and got 00000010011 which interprets to 19 https://wisesocialsmedia.com/story4200287/the-basic-principles-of-bip39-passphrase-generator