Understanding Website Call Conversions
Google website call conversions provide a way for you to measure phone calls to your business that happen as a result of an ad click. When you use this feature, Google dynamically inserts a Google forwarding number on your website so that call information about incoming calls to your business (such as location and duration) can be tracked. Your business will receive phone calls as usual, without interruption to caller ID.
Note:Google Ads Call Tracking or Call Tracking Metrics does not currently work within an iframe. Call tracking is not currently supported in popups, sticky bars, or lightboxes.
This current code is for Google's previous implementation method and will not work with their new Global Site Tag.