I took the index with the words, converted the range to binary, additional 3 zeros, calculated the sha256 digest, took the initial part of the hexadecimal to convert it to binary, added a few zeros into the eight digits in the binary and received 00000010011 which interprets to 19 in https://socialbuzzfeed.com/story4263236/bip39-phrase-generator-can-be-fun-for-anyone