Office 365 PSTN calling on Group Series

Does anyone know if is possible to integrate the Office 365 PSTN calling with the Polycom Group Series? (Running 6.1.2)

Note that I am not trying to register the group series as an endpoint in Skpye for Business. (Do not want "Skype Mode")
We want to be able to use H323 for making video calls and SIP to make phone calls via Office 365 PSTN.

I have searched everywhere and can't seem to find a guide on how to set this up. Is it possible? Does it require the Skpye option/license key?

Thanks,

Scott