You will be able to activate USA Network on Amazon Fire TV by just following some simple steps mentioned below:
Select the search icon and search USA Network.
Select the USA Network app.
Now, Install or Download USA Network.
Open the USA Network channel.
Copy the activation code.
Visit Usanetwork/activatenbcu.
Enter the activation code.
Choose your TV provider.
Now, you just have to Log In with your TV provider to access your favorite shows on USA Network on your Amazon Fire Stick.