作为应用程序进行身份验证

Where you type these things?:

curl -F type=client_cred \
     -F client_id=your_app_id \
     -F client_secret=your_app_secret \
     https://graph.facebook.com/oauth/access_token

In other words, how I'll do it in PHP? Or manually? source

Use the PHP curl function or use the PHP+Javascript example on the page you link to...