I took the index on the words, converted the selection to binary, added 3 zeros, calculated the sha256 digest, took the main Component of the hexadecimal to convert it to binary, included three zeros to your eight digits from the binary and got 00000010011 which interprets to 19 in decimal. https://pr7bookmark.com/story19374783/bip39-seed-phrase-mnemonics-generator-an-overview