I see that back in November of last year, a bunch of people encountered the same problem that I am having now.
I just released my app, and I want to add my store details on the Unity Ads dashboard. So, I click on my project, click Add Store Details (for Google Play), and type in my package name. Then, I click Look Up Game.
This should work, shouldn’t it? Whenever I do this, the box turns red for a brief moment, then I get redirected back to the main dashboard page.