For words that have only 3 letters, there's no 4th letter. Such as with the word “include”, there isn't any far more letters afterwards and so needs to be the word "insert". The word “addict” is inside the BIP39 wordlist but you would've made use of “addi” for “addict”. A https://bookmarksusa.com/story19514393/invalid-bip39-phrase-things-to-know-before-you-buy