I took the index with the words, transformed the range to binary, additional a few zeros, calculated the sha256 digest, took the initial Section of the hexadecimal to transform it to binary, included three zeros to the 8 digits in the binary and obtained 00000010011 which interprets to 19 in https://wildbookmarks.com/story18986489/getting-my-bip39-words-to-numbers-to-work