I took the index with the words, converted the range to binary, added a few zeros, calculated the sha256 digest, took the main part of the hexadecimal to transform it to binary, extra a few zeros to your eight digits in the binary and bought 00000010011 which translates to 19 https://peakbookmarks.com/story18927821/examine-this-report-on-bip39-mnemonic-phrase-tool