I took the index on the words, transformed the quantity to binary, added 3 zeros, calculated the sha256 digest, took the initial Section of the hexadecimal to convert it to binary, included three zeros on the eight digits of the binary and acquired 00000010011 which translates to 19 in decimal. https://cruxbookmarks.com/story19073724/the-fact-about-valid-bip39-seed-phrase-that-no-one-is-suggesting