I took the index in the words, transformed the selection to binary, additional 3 zeros, calculated the sha256 digest, took the main Section of the hexadecimal to transform it to binary, additional a few zeros for the eight digits from the binary and obtained 00000010011 which interprets to 19 in https://extrabookmarking.com/story19004704/considerations-to-know-about-bip39-seed-phrase-generator