I took the index of your words, converted the number to binary, added 3 zeros, calculated the sha256 digest, took the main part of the hexadecimal to transform it to binary, additional 3 zeros into the eight digits of your binary and got 00000010011 which translates to 19 in decimal. https://royalbookmarking.com/story18795109/bip39-seed-phrase-fundamentals-explained