After inputting your Amazon Firestick into your TV, navigate your way to the Amazon store and search for Peacock TV. Install the App and sign-in to your account to start streaming on this platform. 

You can enjoy shows from your Peacocktv.com/tv by directly watching them on your Smart TV, and if this is not the case, you can always screen mirror this streaming service to your TV. Before signing up for Peacock TV, you can read through the details concerning subscriptions and compatibility above.
If you have an iPhone, the easiest way to accomplish this task is to use AirPlay or AirDroid Cast which also allows you to mirror your PC to TV. The last alternative is to use external devices like Chromecast, Roku TV, Amazon Fire Stick, and Apple TV.