For words that have only three letters, there isn't a 4th letter. Such as with the word “incorporate”, there aren't any more letters Later on and thus needs to be the word "include". The word “addict” is in the BIP39 wordlist however, you would have employed “addi” for “addict”. Tips https://bookmarks4seo.com/story18834598/invalid-bip39-phrase-things-to-know-before-you-buy