If you have integrated a facebook page and still doesn't get message, there is a chance that you have another app integrated and chosen to be primary receiver.
To make messages go to all apps equally, here are the steps:
1.go to your FB Page Settings. Choose Advanced Messaging in the list of menu.
2.Make sure there is Qiscus Chat in the list of connected Apps. On the Messenger receiver icon, click Configure on the screenshot below
3.On the popup menu, deselect the Primary Receiver by choosing the same app to remove the check mark.
4.The result should be like screenshot below where there is no Primary Receiver.
5. Wait 5 minutes for the change to happen, then test sending message to your FB Page.