Create fb.php

You can include any opened facebook group wall even you didn't a member of it, and you can include any closed facebook group, but you should be a member of it,
Please follow this three steps and run this code ...

1) Get an access token from https://developers.facebook.com/tools/explorer
2) Get the group ID from this site: lookup-id.com
3) Edit line 28 and 29 .