I took the index with the words, converted the selection to binary, additional three zeros, calculated the sha256 digest, took the 1st Component of the hexadecimal to transform it to binary, additional 3 zeros to the eight digits from the binary and obtained 00000010011 which interprets to 19 in decimal. https://thebookmarkplaza.com/story19400065/top-guidelines-of-bip39-word-list-pdf