Improve the php-module of requests to GetCourse

Hello
Theres a basic piece of php code with cURL requests thats checked and works (generally speaking, its dumb as a cork, like the getcourse API itself).
On its basis, it is possible to increase the number of API-covered getcourse.

The first of the tasks (a total of 5-6 methods is needed):
1) Get a list with **customer subscriptions** (as a result, each customer will have a subscription start/end date).

P.S. For tests, get your own ac getcourse (it is 14 days free), or I will give my test. Or, if you are in the topic, then you already have your own paid ACC.