I took the index from the words, converted the amount to binary, added three zeros, calculated the sha256 digest, took the primary Element of the hexadecimal to convert it to binary, extra 3 zeros to your eight digits of the binary and acquired 00000010011 which interprets to 19 in decimal. https://kingbookmark.com/story18887994/bip39-seed-phrase-mnemonics-generator-an-overview