I took the index with the words, converted the variety to binary, included 3 zeros, calculated the sha256 digest, took the very first Component of the hexadecimal to transform it to binary, included three zeros to your 8 digits in the binary and bought 00000010011 which translates to 19 in https://yesbookmarks.com/story19128267/new-step-by-step-map-for-bip39-english-words