I took the index of the words, converted the quantity to binary, included a few zeros, calculated the sha256 digest, took the initial Portion of the hexadecimal to transform it to binary, added three zeros to the 8 digits of your binary and received 00000010011 which interprets to 19 in https://bookmarksusa.com/story19062911/an-unbiased-view-of-bip39-seed-phrase-github