I took the index with the words, transformed the quantity to binary, included a few zeros, calculated the sha256 digest, took the 1st Element of the hexadecimal to transform it to binary, extra 3 zeros on the 8 digits in the binary and got 00000010011 which interprets to 19 in https://bookmarkspy.com/story20255347/bip39-seed-phrase-fundamentals-explained