I took the index on the words, transformed the amount to binary, added 3 zeros, calculated the sha256 digest, took the first Component of the hexadecimal to transform it to binary, added three zeros on the 8 digits on the binary and obtained 00000010011 which interprets to 19 in decimal. https://socialevity.com/story20633141/considerations-to-know-about-bip39-seed-phrase-generator