The solution you seek - given the info you’ve provided - is well beyond something that can be answered in a post here.
You say everything is correct (few details), but it doesn’t work.
Well, obviously everything is NOT correct. A detailed step by step description of what you did would be needed to even guess at the solution.
You installed the Behringer Drivers
You opened Cubase and the Driver shows up in Devices/Device Setup/VST Audio System and you selected it.
You Created a new empty Project in Cubase.
You know how to route signals on your Mixer to it’s Record/USB Output and you did so.
You looked at your Input meters from the Behringer in the Cubase Mixer and saw this signal.
You added an Audio Track to the project and Selected - using the Inspector in the Arrange page - this Input Channel as the source for the Audio Channel.
You clicked on the “Monitor” button on this Audio Channel.
You now saw the signal from the Mixer on the Audio channels meters.
Your Cubase has Audio from the Behringer. Success. Problem Solved.
Now . . .
Hearing it is another thing:
The Audio Channel needs to be routed to the Main Outs (No Control Room for Now).
The Main Outs (F4) need to be routed to the Behringer.
And you then need to make sure - on the Behringer - that this USB Audio source is routed to the outputs that your Monitors or Headphones are connected to and turned up.