How important is my heat shield? (2007 Honda Civic)

Had to take rear heat shield off from my Honda civic, is this important?

Yes, it is important or it wouldn’t BE there in the first place. Get it put back on.

Any muffler shop can repair this .

Heat shield came off rear above muffler on a Honda civic 2007 2.2 diesel, do I need it replaced imedeitly

Maybe not this minute but as soon as you can. While something bad might not happen why take the chance when it is an easy fix like this.