I took the index of the words, converted the number to binary, added three zeros, calculated the sha256 digest, took the 1st Element of the hexadecimal to transform it to binary, extra three zeros to the eight digits of your binary and got 00000010011 which interprets to 19 in decimal. https://mysitesname.com/story8665549/considerations-to-know-about-bip39-seed-phrase-generator