I took the index of your words, transformed the selection to binary, added 3 zeros, calculated the sha256 digest, took the main Portion of the hexadecimal to convert it to binary, included three zeros to your 8 digits on the binary and acquired 00000010011 which translates to 19 in decimal. https://pr6bookmark.com/story18987047/the-ultimate-guide-to-bip39-seed-phrase-mnemonics-generator