Scure bip39 npm https://penzu.com/p/2ea6922b70254307 While it utilizes BIP32 approach it is possible to still import BIP39 seeds into Electrum wallet. Also other than BIp32 There's BIP44 version which some wallet use with the technology of seeds. For words that have only three letters, there is absolutely no 4th letter. One https://yourbookmarklist.com/story21016894/bip39-standalone-a-secret-weapon-for-bip39-mnemonic-code-converter-tool-https-linktr-ee-bip39