FB event firing only on confirmation form submit

Hi all,

I’m hoping someone can help with an issue I’m having -

In short - How do I get it so that the FB event script only fires once when someone submits the form and then not again?

All the details:

I’ve successfully got the FB pixel event firing when a person completes a form and is forwarded to a landing page by adding the event script to the confirmation page. The issue is, if they refresh the confirmation page, or get end up back their based on our email marketing (since our confirmation page is where users go when they confirm their email address), the pixel is firing again, leading to incorrect stats showing in Facebook.

How do I get it so that the script only fires once when someone submits the form and then not again?

If it helps, here is the landing page/user journey for you to see what I mean: https://wearethedreammakers.com/win-a-holiday/

Thanks!
Ben