I took the index in the words, transformed the selection to binary, included three zeros, calculated the sha256 digest, took the primary A part of the hexadecimal to convert it to binary, extra three zeros on the 8 digits of your binary and acquired 00000010011 which interprets to 19 in https://tvsocialnews.com/story4417383/a-secret-weapon-for-bip39-words-to-numbers