Facebook provide an extension for the Chrome browser called the Pixel Helper Tool which can be found here:
You can use this tool to check the general setup of the Pixel and whether the events appear to be working. Please note that the helper tool is a developer tool that gives a general indication and in many cases may misread or not show events at all due to how the tool works and the coding of your specific site.
Please see this video for an explanation of how the tool may report multiple events:
Please see this video for an explanation of why the tool may not display an ATC event
You can check the events are being reported to Facebook by opening Facebook Business Manager and looking in the Pixels section. Please note that these stats are not instant, and often are delayed before being reports.
You can also check the Purchases that are reported to Facebook match those in your store by using the logs section of the Pixel Perfect app