You can view the detailed instruction on how to assign your reserved phone numbers to Products.
Go to the Publisher Management > Promo Materials > Phone Numbers section.
Go to the Reserved Phone Numbers tab and the list of all your reserved phone numbers will be displayed.
Select "Edit" under the Action column:
Select the Product you would like to assign this number to;
Select Publisher you would like to assign this number to;
Click "Save".
You can see your reserved phone numbers by clicking the "Reserved Phone numbers" tab.