I took the index with the words, transformed the selection to binary, added three zeros, calculated the sha256 digest, took the initial A part of the hexadecimal to convert it to binary, additional 3 zeros to the eight digits of the binary and acquired 00000010011 which interprets to 19 in https://fatallisto.com/story8557796/bip39-seed-phrase-mnemonics-generator-an-overview