I took the index on the words, transformed the variety to binary, included 3 zeros, calculated the sha256 digest, took the first part of the hexadecimal to convert it to binary, additional a few zeros towards the eight digits of your binary and received 00000010011 which interprets to 19 in https://zenwriting.net/keenanctdp/h1-b-unlocking-the-power-of-bip39-a-comprehensive-look-at-word-lists-and