I took the index from the words, converted the selection to binary, included three zeros, calculated the sha256 digest, took the 1st Component of the hexadecimal to transform it to binary, included a few zeros on the 8 digits with the binary and obtained 00000010011 which translates to 19 in https://wiishlist.com/story19771792/the-ultimate-guide-to-bip39-seed-phrase-github