I took the index of your words, converted the amount to binary, additional a few zeros, calculated the sha256 digest, took the first Element of the hexadecimal to convert it to binary, additional a few zeros for the 8 digits of the binary and bought 00000010011 which translates to 19 https://bookmark-share.com/story18852323/getting-my-bip39-words-to-numbers-to-work