Your understanding is right. To test this you need to have a public facing staging/test environment(Web server) which can be accessed publicly. Then you restrict everyone but facebook.
The domain in your URL is not public facing and hence is not accessible over the internet.
Current domain is for intranet so that computers within your organisation can reach to it.
You will have to make it public-facing for connecting it to your app.
Can i say , we need a frontal server which hosts this public facing URL and use that in ACM ?
if this is the case will campaign post the message to facebook via this server?
Attached is the screenshot , which shows Canvas URL and error...
Can you please specify the exact error message and the canvas URL that you are currently using.
Screenshots will help.
Thanks for your response..
I have gone through the URL, you have mentioned.
ACM is installed at our end and when I enter the application server path in Canvas URL.
Application is unable to connect to Facebook..
Please have a look at the documentation link which should answer your query.