Click on the Groups tab on the top navigation bar.

Click on the New Group drop down and select Public Telephone group.

Fill in the session details and choose the options you'd like to apply to this call.

Select contacts with the facilitator role and add them to the session by clicking Add.

From the prompt, choose how the facilitator will join the call.

Once you've chosen the joining method for the facilitator, click Add facilitator.

Repeat this step for all required facilitators.

Take note of the public telephone number to provide your guests, and click Create session to submit the details and be taken back to the calendar.