To install the pixel, we highly recommend that you add its base code between 
the opening and closing  tags on every page where you will be tracking 
website visitor actions. Most developers add it to their website's persistent 
header, so it can be used on all pages.

Placing the code within your  tags reduces the chances of browsers or 
third-party code blocking the pixel's execution. It also executes the code 
sooner, increasing the chance that your visitors are tracked before they leave 
your page.

Once you have added it to your website, load a page that has the pixel. This 
should call fbq('track', 'PageView'), which will be tracked as a PageView event 
in the Events Manager.