I took the index on the words, converted the amount to binary, included a few zeros, calculated the sha256 digest, took the first part of the hexadecimal to convert it to binary, extra a few zeros for the 8 digits of the binary and obtained 00000010011 which translates to 19 https://thebookmarknight.com/story18813890/getting-my-bip39-words-to-numbers-to-work