I took the index with the words, converted the quantity to binary, included three zeros, calculated the sha256 digest, took the 1st A part of the hexadecimal to transform it to binary, added 3 zeros to the 8 digits of your binary and bought 00000010011 which translates to 19 in https://socials360.com/story9505842/top-guidelines-of-bip39-word-list-pdf