I took the index from the words, converted the number to binary, additional 3 zeros, calculated the sha256 digest, took the primary Section of the hexadecimal to transform it to binary, added three zeros to the eight digits of your binary and obtained 00000010011 which interprets to 19 in decimal. https://setbookmarks.com/story18865127/an-unbiased-view-of-bip39-seed-phrase-github