I took the index from the words, transformed the selection to binary, included a few zeros, calculated the sha256 digest, took the main Portion of the hexadecimal to transform it to binary, extra 3 zeros for the 8 digits of your binary and received 00000010011 which translates to 19 in https://ztndz.com/story21850012/bip39-phrase-generator-can-be-fun-for-anyone