I took the index from the words, converted the amount to binary, extra 3 zeros, calculated the sha256 digest, took the 1st Element of the hexadecimal to transform it to binary, additional a few zeros towards the eight digits of your binary and acquired 00000010011 which interprets to 19 in https://bookmarksknot.com/story20493587/the-definitive-guide-to-bip39-seed-phrase