I took the index on the words, converted the selection to binary, included three zeros, calculated the sha256 digest, took the primary A part of the hexadecimal to convert it to binary, added a few zeros to your eight digits with the binary and obtained 00000010011 which interprets to 19 https://prbookmarkingwebsites.com/story22073051/getting-my-bip39-words-to-numbers-to-work