Bip39 json https://collinmmss433.lucialpiazzale.com/from-concept-to-fact-generating-bitcoin-addresses-with-bip39 3a43fced052690635cc9fdce418514528b000dff3eaa5b986ea7be809062e775f2fe99c76733ff200b56fb70cac7c6ac7818b1e8139192a70fe274f5bf57fa46 For words that only have three letters, there's no 4th letter. For example with the word “add”, there won't be any additional letters afterwards ... https://franciscougju442.bravesites.com/entries/general/Produce-Bitcoin-Addresses-from-Seed-Every-Little-Thing-You-Required-to-Know