I took the index on the words, converted the selection to binary, added three zeros, calculated the sha256 digest, took the very first Portion of the hexadecimal to convert it to binary, additional three zeros for the 8 digits from the binary and bought 00000010011 which interprets to 19 in https://telebookmarks.com/story9203875/top-guidelines-of-bip39-word-list-pdf