I took the index in the words, transformed the amount to binary, included three zeros, calculated the sha256 digest, took the very first Section of the hexadecimal to convert it to binary, additional 3 zeros on the eight digits of your binary and got 00000010011 which translates to 19 in https://pageoftoday.com/story4212736/considerations-to-know-about-bip39-word-list-pdf