WebRequests can be instantiated like any other object. Two constructors are available:
The standard, parameter-less constructor creates a new UnityWebRequest with all settings blank or default. The target URL is not set, no custom headers are set, and the redirect limit is set to 32.
The second constructor takes a string argument. It assigns the UnityWebRequest’s target URL to the value of the string argument, and is otherwise identical to the parameter-less constructor.
Ejemplo
UnityWebRequest wr = new UnityWebRequest(); // Completely blank
UnityWebRequest wr2 = new UnityWebRequest("http://www.mysite.com"); // Target URL is set