You will need to change
YOUR_ID to the ID you can find in Facebook’s tracking code.
I created this by adopting the noscript src from their sample script for use in amp-pixel. More advanced usages would be possible, but ideally Facebook would provide the respective documentation.
<amp-pixel src="https://www.facebook.com/tr?id=YOUR_ID&ev=PageView&noscript=1" layout="nodisplay"></amp-pixel>