I took the index of the words, transformed the selection to binary, added a few zeros, calculated the sha256 digest, took the initial Portion of the hexadecimal to convert it to binary, additional three zeros towards the 8 digits from the binary and got 00000010011 which translates to 19 in https://mysitesname.com/story8618804/getting-my-bip39-words-to-numbers-to-work