Hey, scotbradly726.
I see that when you try to answer an incoming phone call, it immediately reports that the call failed. I'll be glad to help.
If you can‘t make or receive calls on your iPhone -- Follow each of the steps provided in this support article.
You might not be able to make or receive calls on your iPhone if you have certain settings turned on, if your software isn't up to date, or if there's a problem with your network.
Cheers!