For words that have only 3 letters, there is no 4th letter. As an example with the word “insert”, there won't be any additional letters Later on and therefore has to be the word "add". The word “addict” is from the BIP39 wordlist but you might have employed “addi” for https://scrapbookmarket.com/story18822800/new-step-by-step-map-for-ledger-seed-phrase-bip39