Set default audio options
Customize your default audio options across your account to streamline the creation of new sessions. You can change these settings for each session as needed.
Note: Changing your settings will only impact the webinars that you schedule after that point. It will not affect previously scheduled sessions – you must change those manually if desired. See Available Audio Modes to learn more about which audio options you can provide to your attendees.
Change default audio options
If you are providing long-distance (toll) or toll-free phone numbers for your customers, you can choose which countries are included in the session information for each
webinar.
Change the countries for which phone numbers are provided
If you are providing long-distance (toll) or toll-free phone numbers for your customers, you can choose which countries are included in the session information for each
webinar.
Choose a preferred phone number
If you are providing multiple countries in the list of long-distance (toll) or toll-free phone numbers shown to your customers, you can choose which country appears first in the list by designating it a "preferred country". If you don't choose a preferred number, the phone number that's displayed to attendees first by default is the billing country you have associated with your account.
When selecting which countries are included, selecting the Star icon next to the country you want to be preferred. You can only select 1 preferred country.
Result: It will turn blue 
.