For words that have only 3 letters, there is absolutely no 4th letter. One example is with the word “incorporate”, there are no additional letters afterwards and so must be the word "insert". The word “addict” is in the BIP39 wordlist however, you might have utilized “addi” for “addict”. Unlock https://greatbookmarking.com/story18939644/the-invalid-bip39-phrase-diaries