Facebook channel create

[Landry]

Hi,
I'm trying to connect my facebook page to RapidPro. I can log in with Facebook and create facebook channel. I created the Facebook app, copied the various secret codes from Facebook Developer, and pasted them into RapidPro (settings_common.py). But RapidPro isn't receiving any messages from my facebook page. What should I do?

Where can I find this URL in the form "https://your-rapidpro-instance.com/c/fb/<UUID>/receive"?

Thank you in advance for your help.