I took the index on the words, converted the quantity to binary, added three zeros, calculated the sha256 digest, took the main Portion of the hexadecimal to convert it to binary, extra three zeros to your eight digits of the binary and got 00000010011 which translates to 19 in decimal. https://thebookmarkplaza.com/story18754446/the-ultimate-guide-to-bip39-seed-phrase-mnemonics-generator