When you create the APP-ID at developer.paypal.com (see the Adaptive API calls overview of applications), you configured which applications to use. Some functions are considered “basic” and do not require any special permissions, and your application will have the status “ Approved automatically ” if your application needs some special functions (for example, seconded payments) that your application will have in order to receive the verification status, and the status will be " Conditionally Approved ." This means that you can use basic functions (for example, simple adaptive payments), but you cannot use special functions until they are approved. In addition, when you create an APP ID, you must indicate that you will use this function (granting permissions to a third-party user) so that APP is enabled to use this function
Edit: It should be noted that when creating an account in the form of a sandbox, your application will include all the functions and will not require any special permissions from Paypal, so do not be fooled by this; because as soon as you go live, it will cause an error if your APP-ID is not approved (or, rather, if it is conditionally approved). The review process can take several weeks, so I advise you to plan ahead and not accept the assumption that if it works in a sandbox environment, it will work in real time by default.