Open play store and type amazon.com/mytv.
Now you can download and install the Prime Video app on your device.
Then you open the Prime Video app.
Register your device by selecting Register on the Amazon website.
You will be given a code to enter on a given website.
Register your device by selecting sign in to enter your account information directly.
To register your device using a registration code.
Find the 5-character registration code on your device by selecting Amazon Video home screen.
From your computer, go to Register Your Compatible TV or Device.
choose "register on the Amazon website" to get six-letter registration code.
Enter your registration code in the text box.
Then code to enter in your account.