For words that have only 3 letters, there's no 4th letter. Such as with the word “add”, there are no extra letters Later on and so needs to be the word "incorporate". The word “addict” is within the BIP39 wordlist however, you would have applied “addi” for “addict”. Standard recovery https://bookmarkinglife.com/story4391176/a-review-of-bip39-phrase-list