---
title: Reproducing the ‘fbq is not defined’ checkout error
description: "The 'fbq is not defined' error only appears on a checkout page that you reach through the normal booking flow. **To reproduce it:** 1. Open a property…"
url: "https://homerunner.io/docs/how-can-i-reproduce-the-fbq-is-not-defined-error-on-a-homerunner-checkout-page-t/"
updated: "2026-10-26"
category: Booking engine and checkout
---

# Reproducing the ‘fbq is not defined’ checkout error

The 'fbq is not defined' error only appears on a checkout page that you reach through the normal booking flow.

**To reproduce it:**

1. Open a property page and pick dates.
2. Click **Book Now** to reach a populated checkout.

**Why an empty checkout does not show it.** If you open an empty checkout page directly, the begin_checkout data layer event is not triggered, so the error does not appear.

Still stuck? [Contact the HomeRunner team](https://homerunner.io/contact/) with your site address and what you tried, and we take it from there.