How to display the element I need in the ViewPager?

Question

Android

Hello! I am using Material Camera
library . The MainActivity.java main screen has two buttons that launch different modes through the MaterialCamera.java file in the application library - video and photo. The file itself leads to activities that open further fragments. As you already understood, I want to know how you can make the video camera immediately open in one ViewPager, and the camera in another, without pressing the buttons, respectively. I'm trying to use the ViewPager from here, though I'll be very happy with other options, it doesn't really matter to me: download When I try to just run the MaterialCamera in the ViewPager, of course, it crashes....
I really, really, really hope for your help, your suggestions for solving this problem. Many thanks to everyone in advance!