I took the index on the words, transformed the selection to binary, included three zeros, calculated the sha256 digest, took the primary part of the hexadecimal to convert it to binary, additional a few zeros for the 8 digits on the binary and got 00000010011 which translates to 19 in https://bookmarkmiracle.com/story20569709/new-step-by-step-map-for-bip39-english-words