I took the index with the words, transformed the quantity to binary, extra 3 zeros, calculated the sha256 digest, took the main Element of the hexadecimal to transform it to binary, included three zeros towards the 8 digits from the binary and received 00000010011 which interprets to 19 in decimal. https://pukkabookmarks.com/story19019915/the-ultimate-guide-to-bip39-seed-phrase-github