NEED HELP- Catalytic Converter Front Gasket

so I had an exhaust leak for some time now and finally had time to look at the car. when I propped the car up, I found out that the previous owner had installed the gasket was burned off halfway so resulting in the nut flying off. but when I looked up the gasket on Acura parts it shows this circular gasket as opposed to the flange gasket installed in the car. so I'm wondering which one I should install or the circular OEM one or just buy another flange gasket.