Help, Fx Impact missing part at breach and magazine.

I just bought my wife an Impact for her birthday. We were sighting in her scope when the guide for the magazine went missing. I dont know what this is called or how hard its going to be to replace. Any help would be appreciated.

I did search for an answer but couldnt find any results. Perhaps because i dont know what the part is called?

Thank you
 
I need to recheck my settings, i didnt get any notifications of your replies.

Thank you for the help. It was user error.

I dont have any experience with the impact, it took me some time to sort out the problem.

The screw that retains the barrel was loose (from factory) and when she double loaded the barrel, the pellet probe, experiencing resistance, pushed the barrel forward enough that it no longer aligned the magazine.

We thought there was a additional piece shaped like the detent in the magazine. But i saw in image of the brass breach online protruding from the breach block and I connected the dots. 

My wife was very upset and ready to mail it back to the factory. Glad I inaisted on trying to resolve the problem at home.