I took the index of your words, converted the amount to binary, included 3 zeros, calculated the sha256 digest, took the main Portion of the hexadecimal to transform it to binary, included three zeros to your 8 digits on the binary and bought 00000010011 which interprets to 19 in decimal. https://getsocialselling.com/story4398205/the-ultimate-guide-to-bip39-seed-phrase-mnemonics-generator