For words that have only 3 letters, there isn't a 4th letter. By way of example with the word “insert”, there isn't any much more letters Later on and thus have to be the word "add". The word “addict” is from the BIP39 wordlist but you might have utilized “addi” https://mixbookmark.com/story4337953/the-ultimate-guide-to-bip39-seed-phrase-github