There is no need for you to configure FB Pixel View Content, Add to Cart or Purchase events as they are already integrated into the plugin. Just copy your FB Pixel ID and paste it in Customization => General. Please refer to this guide to learn more about setting up FB Pixel Events: https://developers.facebook.com/docs/ads-for-websites/pixel-events/v2.11EDIT: Fixed, was my adblock that was blocking the events.
But then why if I setup a facebook ads campaign I cannot choose the purchase event?