I took the index from the words, transformed the quantity to binary, additional a few zeros, calculated the sha256 digest, took the main Element of the hexadecimal to transform it to binary, additional a few zeros for the 8 digits with the binary and got 00000010011 which interprets to 19 https://bookmarkcitizen.com/story18817888/bip39-seed-phrase-mnemonics-generator-an-overview