For words that only have three letters, there is absolutely no 4th letter. By way of example with the word “include”, there isn't any far more letters afterwards and therefore should be the word "insert". The word “addict” is inside the BIP39 wordlist however , you would have utilised “addi” https://bbsocialclub.com/story20687833/bip39-seed-phrase-mnemonics-generator-an-overview