I took the index on the words, converted the variety to binary, added three zeros, calculated the sha256 digest, took the main A part of the hexadecimal to convert it to binary, added three zeros towards the eight digits of your binary and received 00000010011 which translates to 19 in https://socialwoot.com/story20460314/an-unbiased-view-of-bip39-seed-phrase-github