L298n

How do you connect 2 L298n to one arguing uno?

I suggest to pick an Uno that does not argue.

Desmore:
How do you connect 2 L298n to one arduino uno?
have a project that requires two L298n and the Arduino uno processor.

Have you got one L298N chip connected and running? Having two pretty much means you duplicate the connections to each motor's INx and ENx pins from other available Uno pins. (Along with motor power, logic power and grounds of course.)

But maybe you mean you have a L298N shield not just chips? In that case you would need to show some details, and it might not be possible.