How much will it cost to get my underbody engine cover fixed
You will have to call a few places near you for actual estimates . The people here don’t know where you are, who you might use for the repair and without seeing the cover have no idea what it will take to fix it.
Maybe I’m seeing the picture wrong, but that looks like the cat heat shield to me.
Sometimes parts like this are available new only from the dealer, which can be pricey. If that’s more than you are willing to pay, consider getting it used, from an auto recycler, and have a local non-chain muffler shop do the work.
I’m not really sure what it is but I figured It was the underbody engine
It is not under the engine. It looks to be a heat shield under or around the catalytic converter or something else in the exhaust system, aft of the engine.
Do I need to get it fixed asap and do you have an estimate of how much
That’s a question a mechanic can answer after lifting and inspecting under the car. Generally a heat shield is not critical to the car’s functioning, but it reduces the possibility of burning the carpet or starting a grass fire. But you and I will only feel OK about it after someone competent takes a good look.