I took the index from the words, converted the quantity to binary, added three zeros, calculated the sha256 digest, took the first Portion of the hexadecimal to transform it to binary, extra a few zeros to your eight digits with the binary and bought 00000010011 which translates to 19 in https://bookmarkoffire.com/story19527901/getting-my-bip39-words-to-numbers-to-work