Step 1: Testing in sandbox
When your integration is complete, simply launch your game, tap the Skillz button, and begin testing in the Skillz sandbox environment.
Step 2: Moving to production
When your game is fully tested and ready for production, it's time to switch the environment from Sandbox to Production.
For Unity iOS, you can switch from Sandbox to Production by going to your game's SkillzDelegate Game Object which was automatically generated when you followed Step 8 of the Unity iOS integration document. Here is a screenshot for your reference.
Note: Make sure to upload your binary in the Skillz Developer Portal each time you make a
change in your game. If you haven't, here's a screenshot to show you how to do that: