Bip39 passphrase generator https://www.giantbomb.com/profile/blathayqvn/ While it uses BIP32 strategy it is possible to continue to import BIP39 seeds into Electrum wallet. Also apart from BIp32 there is BIP44 Edition which some wallet use for that technology of seeds. For words that have only three letters, there is not any 4th https://ztndz.com/story25023804/keystone-bip39-the-5-second-trick-for-bip39-mnemonic-code-converter-tool-https-www-youtube-com-channel-ucupxfytj0fb78sq55hu6ocw