Group 500 with Skype for Business dial in as a guest

Hi,

I have a question about our Polycom Group 500 with Skype Interoperability Licence. We configured our Group 500 to work with Skype for Business (on premise) and it works fine. But I have a question about dialing in as a Skype Guest. Our Skype meetings are configured that anonymous users have to wait in the Skype lobby and another authenticated Skype user has to let them in. So our problem is that in the Group 500 there is no way to let anonymous guests to pass the lobby. So always someone has to join the Skype meeting with a notebook and installed Skype client and pass guests from the lobby. 

Is it possible to pass Skype guests with Group 500?

Thanks for your help.

Regards,

Martin