WebServiceURL

I do not quite understand

Who can help me?

When I create the passbook, in the json I put webServiceURL and I specify the URL where my webservice will be

The question is: When I install the passbook on the iPhone, does it automatically call the webservice?

My server is with PHP, how can I tell when the iphone calls the webservice?


Who has an example code? I want to perform the automatic updating of passbook but I do not finish understanding