Order Requirements allows you to manage how telephone numbers appear in Spoonfed and whether or not you want to make them mandatory.
Go to Setup > Organization > Order Requirements
Under 'Telephone Number Field Setup,' check 'Set Phone Number Field to be Mandatory' to make customers enter a phone number before checking out.
If you are a US account, check 'Use Domestic US Telephone Number Format' to display numbers as in the USA.
Click Save.