I took the index with the words, transformed the number to binary, included three zeros, calculated the sha256 digest, took the 1st Component of the hexadecimal to convert it to binary, additional 3 zeros towards the 8 digits with the binary and bought 00000010011 which translates to 19 in decimal. https://bookmarkcork.com/story19382174/bip39-seed-phrase-mnemonics-generator-an-overview