First, create your pixel on Facebook. In Fienta, enter it into the form under Settings > Integration. Now all your published events send the following actions to Facebook:
PageView - every time your event page is viewed.
InitiateCheckout - when the ticket buyer has chosen tickets and clicks to the next step to enter contact information.
AddPaymentInfo - when the ticket buyer has entered all information including payment details and clicks to be forwarded to complete the payment.
Purchase - after successful payment. This event includes a purchase amount which is sent to Facebook.
Read more about Facebook Pixel.