The CheckoutX app offers an alternative checkout funnel that takes your customers off the Shopify checkout step pages and processes the transaction on their end.
Enabling Trackify (including TrackifyX) is simple: Just navigate to the Integrations menu in CheckoutX and check the box under Trackify:
We recommend that - before running actual traffic - you run a transaction yourself and go through the entire funnel to confirm that everything is working as expected!
The best tool to monitor pixel events when you do that is the Test Mode in Facebook's Event Manager. Here is a video that shows how to use that.