Step One.
First you have to enable "downloads from unknown sources" and "debugging mode" in the Developer Options.
To do this, please Go to > Settings > My Fire TV > About > My Fire TV Stick 4K or My Fire TV Lite > Click On It For 7 Times Until The System Says (You are Already A Developer).
Then Go back to > Settings > Device or My Fire TV > Developer Options > Set both to ON
Step Two.
Install the Downloader App (Orange Icon App with Arrow Pointing Downwards), you can install this app by searching for it on the Firestick home screen, on the magnifying glass in the top left corner of the home screen type Downloader. Scroll down to downloader in the suggestions below.
Once you have clicked it, You will be taken to the download screen, please install.
Step Three.
Once installed please open Downloader and enable JavaScript from the settings menu on the left hand side of the screen on the downloader app and type in any of the following URL to install Afiniti TV App via Downloader.
Step Four.
Once Installation is complete, please open the app and enter your login details supplied to you via Email once You complete your Order. Please check your Email Inbox & Spam Folder to find the Login Details.
Now, you’ve completed the setup on your Firestick and you’re good to go!