If you are trying to watch Sunday Night Football without a local NBC station, you are not alone. I switched to streaming service about a year ago. There are a few things that I have to change to get local sports. I currently use PS Vue for the majority of TV watching, and Amazon Prime for movies, etc. However, I do not get NBC or ABC via PS Vue, and I am unable to get them using an over the air antenna.
Starting the end of September, I will be able to make up for some of the NBC games by using Amazon Prime, however that does not start for a few weeks. So, when I want to watch the Cowboys and the Giants tonight, I will be using the NBC Sports app on FireTV. There are other options available, depending on where you live and your local restrictions, etc. I know some people are able to use HuluTV, while others can use NFL on Verizon. I have NFL on Verizon as an option, but prefer to watch the game on a 55 inch TV instead of a 5 inch phone.