Bip39 Npm Regardless that it uses BIP32 method you may still import BIP39 seeds into Electrum wallet. Also in addition to BIp32 There may be BIP44 Variation which some wallet use with the era of seeds. It is possible to see the total resource code in standalone, offline html file. https://bookmarkspy.com/story20034001/seed-phrase-generator-javascript-an-unbiased-view-of-seed-phrase-generator