Bip39 api https://www.hometalk.com/member/176312665/elva1377050 Though it uses BIP32 system you could nonetheless import BIP39 seeds into Electrum wallet. Also besides BIp32 there is BIP44 Variation which some wallet use for the generation of seeds. For words that have only three letters, there is not any 4th letter. One example is Together https://bookmarkcitizen.com/story20455495/what-is-bip39-seed-the-5-second-trick-for-bip39-mnemonic-code-converter-tool-https-t-me-bip39-chat