For words that have only three letters, there is no 4th letter. Such as with the word “insert”, there are no much more letters Later on and therefore should be the word "include". The word “addict” is during the BIP39 wordlist however, you would've employed “addi” for “addict”. You should https://classifylist.com/story20570088/the-definitive-guide-to-bip39-seed-phrase