I took the index with the words, converted the selection to binary, additional a few zeros, calculated the sha256 digest, took the first Component of the hexadecimal to transform it to binary, added 3 zeros into the 8 digits on the binary and received 00000010011 which interprets to 19 in https://thesocialdelight.com/story4490196/bip39-phrase-generator-can-be-fun-for-anyone