I took the index with the words, transformed the amount to binary, included 3 zeros, calculated the sha256 digest, took the initial A part of the hexadecimal to convert it to binary, added three zeros to the 8 digits on the binary and bought 00000010011 which translates to 19 in https://crossbookmark.com/story18847855/5-simple-techniques-for-bip39-word-list-pdf