I took the index of the words, converted the number to binary, additional 3 zeros, calculated the sha256 digest, took the main Element of the hexadecimal to transform it to binary, additional three zeros to your eight digits from the binary and obtained 00000010011 which interprets to 19 in decimal. https://bookmarkjourney.com/story18852532/helping-the-others-realize-the-advantages-of-bip39-seed-phrase-mnemonics-generator