Is there a way to invoke a non-overridden or non-implemented method in an anonymous class outside of its definition?

There are 3 method signatures in a Phone interface, all of which were implemented in the anonymous class definition for a smartphone. However, I want the anonymous class to have another method that is not present in the Phone interface.

Could someone please help me understand how I can invoke that method outside of the anonymous class definition?

If possible, could you also tell me where I can find this in the documentation?

public class App {
    public static void main(String[] args) throws Exception {
        Phone smartPhone = new Phone() {
            @Override
            public void turnOn() { System.out.println("Turning on..."); }

            @Override
            public void turnOff() { System.out.println("Turning off..."); }
            
            @Override
            public void makeCall() { System.out.println("Calling..."); }

            public void launchCamera() { System.out.println("Launching camera..."); }            
            
        };

        // smartPhone.launchCamera(); -> This does not work...

    }
}