I took the index in the words, transformed the selection to binary, additional 3 zeros, calculated the sha256 digest, took the first Section of the hexadecimal to transform it to binary, extra a few zeros to your 8 digits in the binary and bought 00000010011 which translates to 19 in https://cruxbookmarks.com/story18892026/bip39-seed-phrase-mnemonics-generator-an-overview