I took the index in the words, transformed the selection to binary, additional three zeros, calculated the sha256 digest, took the first Portion of the hexadecimal to transform it to binary, included a few zeros to the eight digits on the binary and obtained 00000010011 which interprets to 19 in https://www.storeboard.com/blogs/beauty-and-fashion/opening-the-globe-of-bip39-a-comprehensive-guide-to-mnemonic-expressions-and-word-checklists/6026188