I took the index in the words, converted the selection to binary, extra 3 zeros, calculated the sha256 digest, took the very first Section of the hexadecimal to transform it to binary, included three zeros on the eight digits of your binary and got 00000010011 which translates to 19 in https://bookmarkstown.com/story19077327/the-fact-about-bip39-seed-phrase-word-list-that-no-one-is-suggesting