I took the index on the words, transformed the selection to binary, added three zeros, calculated the sha256 digest, took the initial Section of the hexadecimal to convert it to binary, added a few zeros to the eight digits of your binary and received 00000010011 which translates to 19 in https://socialaffluent.com/story4441435/new-step-by-step-map-for-ledger-seed-phrase-bip39