For words that only have 3 letters, there is no 4th letter. By way of example with the word “incorporate”, there aren't any a lot more letters afterwards and thus needs to be the word "insert". The word “addict” is while in the BIP39 wordlist but you would've applied “addi” https://rotatesites.com/story20235601/examine-this-report-on-bip39-mnemonic-phrase-tool