Google Ads call reporting comes into play to collect data about your call extension and call-generating ad campaigns. Call reporting is used to measure the performance of all call-only ads, call assets, and location assets. You can monitor details like number of phone calls of a specified duration, and call start time. All can be managed at a single account level.
Google Ads charges advertisers only when the Google forwarding number shown in the ad is clicked.
How to turn on call reporting for all your campaigns?
1. Sign in to your Google Ads account
2. Click “All campaigns” in the left navigation menu
3. Click “Settings” in the page menu, and then click the “Account settings” tab
4. Under “Call reporting,” select “On”

If you want to turn off this feature, select “Off” in the fourth step.