At the time of this writing, EOS does not yet support BIP39 Mnemonic phrase for keys generation. EOS BIP39 support is planned and upcoming, (see here), for now a workaround is to: Use a 12 word phrase

Overview How to change/manage your EOS keys (owner/active) from the command line using the official Docker image from EOSIO. This is a very techincal post, if you prefer a UI you could check out the greymass