I took the index from the words, converted the variety to binary, additional three zeros, calculated the sha256 digest, took the initial Component of the hexadecimal to convert it to binary, extra 3 zeros into the eight digits of the binary and got 00000010011 which translates to 19 in decimal. https://bookmarkproduct.com/story18996686/the-basic-principles-of-bip39-passphrase-generator