I took the index on the words, transformed the amount to binary, added three zeros, calculated the sha256 digest, took the first Section of the hexadecimal to transform it to binary, additional a few zeros on the eight digits of your binary and received 00000010011 which interprets to 19 in https://free-bookmarking.com/story19091003/considerations-to-know-about-bip39-seed-phrase-generator