For words that have only three letters, there isn't a 4th letter. As an example with the word “include”, there isn't any a lot more letters Later on and therefore needs to be the word "insert". The word “addict” is inside the BIP39 wordlist however you would have utilized “addi” https://social4geek.com/story4360524/the-definitive-guide-to-bip39-seed-phrase