For words that have only three letters, there isn't any 4th letter. For instance with the word “insert”, there won't be any more letters afterwards and so should be the word "insert". The word “addict” is from the BIP39 wordlist however, you might have employed “addi” for “addict”. Unlock your https://bookmarkrange.com/story20213355/invalid-bip39-phrase-things-to-know-before-you-buy