I took the index on the words, transformed the number to binary, additional 3 zeros, calculated the sha256 digest, took the primary Component of the hexadecimal to transform it to binary, extra 3 zeros to your eight digits of your binary and received 00000010011 which translates to 19 in decimal. https://naturalbookmarks.com/story18920167/the-ultimate-guide-to-bip39-seed-phrase-github