Hello,
Pity you've posted only a thumbnail of the photo, but it looks to me like it's a bar that should be welded to this part of the exhaust system.
It goes to the rubber orange part, hanger, which at the other end hangs on the part which is screwed to the body.
Check the
ePER link on the bottom of the forum banner. It's the FIAT spare parts catalogue. Search window is top left of the screen. Put the VIN of you car, then navigate to the correct category and you'll see all the parts and the part numbers.
If there isn't such a bar welded to the exhaust you've bought, perhaps you've bought the wrong one. If it's the only problem, make it weld to the exhaust tube at the correct place / angle.