I took the index with the words, transformed the quantity to binary, extra 3 zeros, calculated the sha256 digest, took the main A part of the hexadecimal to transform it to binary, included a few zeros to the eight digits on the binary and bought 00000010011 which translates to 19 https://socialaffluent.com/story4275236/bip39-seed-phrase-mnemonics-generator-an-overview