I took the index on the words, transformed the range to binary, additional 3 zeros, calculated the sha256 digest, took the very first A part of the hexadecimal to transform it to binary, extra 3 zeros for the eight digits in the binary and acquired 00000010011 which translates to 19 https://bookmarkinglive.com/story19593503/bip39-seed-phrase-mnemonics-generator-an-overview