Hello Millier
The article not publish on Facebook because you have configured only friends see it
Now please help me create again in your Facebook application and
After you config App ID and App Secret please help me click button "Connect with Facebook" and click okey 3 step confirm Facebook (In step 2 please help me chooose is "Publish" see photo
prntscr.com/e0muer). And check it again
Note: In your Facebook appication in tab app review please choose yes in Make public
(see photo
prntscr.com/e0mt8g)
You can see guide in file .doc in package. Or can you send me account Facebook via contact form? We will help you config again
Best regards
Bach Pham