For words that have only 3 letters, there is not any 4th letter. By way of example with the word “insert”, there aren't any more letters Later on and therefore need to be the word "incorporate". The word “addict” is from the BIP39 wordlist but you would've utilized “addi” for https://mysocialguides.com/story4253909/facts-about-bip39-seed-phrase-word-list-revealed