If you failed to test the Facebook pixel, please follow the below steps to find out the root cause.
Make sure you have copied the code we provide to Shopify Customer Events. And make the custom pixel status " connected"
2. Test several more times. If your website installs a lot of elements, the pixel code needs more time to load. Wait for a while and test again.
3. If you still get the warning message, please contact our support team for help.