I took the index from the words, transformed the quantity to binary, included three zeros, calculated the sha256 digest, took the main part of the hexadecimal to convert it to binary, extra a few zeros on the 8 digits in the binary and bought 00000010011 which interprets to 19 in https://bookmarkalexa.com/story4323453/top-guidelines-of-bip39-word-list-pdf