Different UI render order problem

Unity Engine
1

I’ve got two UIs in my game.

One is with Screen Space Camera, and the other one is with Screen Space Overlay.
However, the Screen Space Overlay UI always comes in front of Screen Space Camera UI.

How can I make the Screen Space Overlay UI to render behind the Screen Space Camera UI?

2

You can’t. It’s overlay. It will always overlay everything. They will either both need to be camera or both need to be overlay, then you can change the order in layer if you need to.