I took the index in the words, transformed the number to binary, additional a few zeros, calculated the sha256 digest, took the primary part of the hexadecimal to transform it to binary, additional three zeros to your eight digits in the binary and obtained 00000010011 which translates to 19 in https://wisesocialsmedia.com/story4448184/helping-the-others-realize-the-advantages-of-bip39-mnemonic-phrase-tool