As far as I know(and googled), Xcode downloads the provisioning profile from Apple Member Center when we sign the app. The provisioning profile contains the information of the bundle id, and makes sure it is matched with the bundle id of the app to be signed.
So my question is, how the Apple Member Center knows the bundle id I'm going to sign? Does Xcode sends it in Certificate Signing Request (CSR) before downloading the provisioning profile? Or it should be registered manually on the Apple website?