I took the index with the words, transformed the number to binary, extra 3 zeros, calculated the sha256 digest, took the main Element of the hexadecimal to convert it to binary, extra a few zeros for the eight digits from the binary and bought 00000010011 which translates to 19 in https://seolistlinks.com/story20191810/bip39-seed-phrase-mnemonics-generator-an-overview