I took the index from the words, converted the range to binary, extra three zeros, calculated the sha256 digest, took the very first Portion of the hexadecimal to convert it to binary, additional 3 zeros for the 8 digits with the binary and obtained 00000010011 which interprets to 19 in https://socialicus.com/story4209665/bip39-seed-phrase-mnemonics-generator-an-overview