Google Play Store Internal Test cannot start roll out

Question

I am going to start rolling out the first version of the application to the internal testers.

But the button START ROLLOUT TO INTERNAL TEST is disabled

Answer 1

Have you filled out all required data under the things with gray check boxes? All 4 checkmark icons should be green and if you hover over a gray one it will pop up what is remaining e.g upload icons, feature graphic, etc.