For words that have only three letters, there isn't a 4th letter. One example is with the word “insert”, there are no a lot more letters Later on and thus need to be the word "incorporate". The word “addict” is from the BIP39 wordlist however , you might have made https://fellowfavorite.com/story19974969/how-much-you-need-to-expect-you-ll-pay-for-a-good-valid-bip39-seed-phrase