In https://help.burner.pro/en/articles/9763184-why-doesn-t-burner-have-a-seed-phrase-and-how-is-my-private-key-secured it indicates that the private key is not extractable but https://help.burner.pro/en/articles/9763137-what-is-card-duplicator would seem to necessitate extracting the private key in some manner. How is it possible to duplicate the burner otherwise? Thanks for any clarity you can provide!