I took the index with the words, transformed the number to binary, additional a few zeros, calculated the sha256 digest, took the initial Component of the hexadecimal to transform it to binary, added three zeros towards the eight digits of the binary and obtained 00000010011 which interprets to 19 in https://thesocialcircles.com/story4702512/top-guidelines-of-bip39-word-list-pdf