I took the index with the words, transformed the quantity to binary, additional three zeros, calculated the sha256 digest, took the initial Element of the hexadecimal to transform it to binary, added a few zeros to the eight digits of your binary and obtained 00000010011 which interprets to 19 in https://mysitesname.com/story8546068/getting-my-bip39-words-to-numbers-to-work