How to Set Up Ad Extensions in AdWords:
From your AdWords Dashboard Select the campaign or ad group you would like to add your location to. Ad extensions can be added at the campaign or ad group levels. It is important to remind you that ad extensions are only available for Search Network Only and Search with Display Select Text Ads.
Select the Ad Extensions tab
Click the View: drop-down menu & select [Your Preferred Extension]
Click the EXTENSION button
Follow the Extension-Specific Tutorials
Your extension should be approved within 24 hours