cloud build - only blue screen on web app

I tried first time Cloud Build. I am trying to build a web game. But when i build it and press play I only see blue sreen.

So i created separate project just for this. I changed camera background from blue to red and added 2 cubes.
But I still get only blue screen.

How to fix that? Thanks!

I got anwered here on this forum.
All I had to do is :
in editor go File → Build Settings, then add my scene under the “Scenes in Build” and make sure it’s the first one in the list.