I read all the steps to follow Your game must clear a basic UDP Sandbox test before its first release. UDP will verify that your game initializes and purchases IAP items properly before letting you release your first revision and move to the submission stages. How to complete this step?Collapse First, be sure to create UDP Sandbox Test accounts. You can do this in the section directly below, or in the Unity Editor. (Done) Run your UDP APK on an emulator or a real Android device. (Done) Use your UDP Sandbox Test account credentials to log in. (wait how do I do that ?) Test your game, and make at least one IAP transaction. It's a sandbox environment, no real money is involved! During the course of the above steps, your game will call the Initialize() and Purchase() methods. You will see the results during your sandbox testing, and UDP will also capture the results on its back-end. The most confuse step is when running on a real device, also the test account I mean I have to use my Unity account here ? I'm confused in this step. Also what about when my game don't use IAP ? Probably not necessary but do I really need IAP to use UDP ?