I took the index from the words, converted the number to binary, included a few zeros, calculated the sha256 digest, took the main Component of the hexadecimal to transform it to binary, additional 3 zeros on the 8 digits from the binary and got 00000010011 which interprets to 19 in https://bookmarktune.com/story18740956/top-guidelines-of-bip39-word-list-pdf