I took the index in the words, transformed the range to binary, included 3 zeros, calculated the sha256 digest, took the main Section of the hexadecimal to transform it to binary, additional 3 zeros to the eight digits of the binary and acquired 00000010011 which translates to 19 in decimal. https://bookmarkcork.com/story19583791/the-ultimate-guide-to-bip39-seed-phrase-mnemonics-generator