Users will only be able to call into virtual public meetings if phone capability has been enabled for the survey where the meeting is housed. To enable phones, navigate on the platform to the Phone tab and toggle on the option to Enable Phone:

If this option is not toggled on, users will be notified when calling into the meeting that phone capabilities have not been enabled and they will not be able to speak.

See also:

Accepting voicemail comments

How callers can choose between meetings running at the same time
​Managing phone participants in a virtual meeting

How callers can choose between meetings running at the same time