You may not be able to access a conversion-tracking pixel that has previously been shared with you, because the person who shared it with you has stopped sharing it or deleted it. If you delete a shared pixel yourself, you will no longer be able to access it, but it will still be available to the person who created it.

If the person you share the conversion-tracking pixel account with has unshared or deleted it, you should receive an email notifying you of this change.

You can go to your Adverts Manager to view your existing conversion-tracking pixels.

* Nguồn: Facebook