The guest speaker option allows specific callers to be unmuted throughout the call with the host while the rest of the attendees are on mute.
Your guest speaker code is located under My Account > Conference Codes.
To use this option, provide your guest speakers with the following steps:
Dial-in number
6-digit Conference Code
When joined into the conference, press 88* (a prompt will ask for the guest speaker code)
5-digit Guest Speaker Code