I took the index with the words, converted the amount to binary, included three zeros, calculated the sha256 digest, took the main Element of the hexadecimal to transform it to binary, extra a few zeros into the eight digits from the binary and obtained 00000010011 which translates to 19 in https://monobookmarks.com/story19517725/new-step-by-step-map-for-bip39-english-words