I took the index on the words, transformed the selection to binary, additional a few zeros, calculated the sha256 digest, took the initial Element of the hexadecimal to convert it to binary, added 3 zeros to the 8 digits with the binary and got 00000010011 which translates to 19 in https://bookmarkcitizen.com/story19038291/helping-the-others-realize-the-advantages-of-bip39-mnemonic-phrase-tool