For activating HBO GO on your Amazon Fire TV-
1) Firstly, head to download the HBO GO app on your Amazon Fire TV.
2) Then, unlock the HBO GO on your device.
3) After that, you need to choose “Activate your Device” for getting the activation code. Just stay on the page, until you enter the received code on the computer.
4) After that, just head to HBOGO.com/activate.
5) Then, select your Amazon Fire TV and then choose Continue.
6) Now, head onto select your TV provider and then enter the credentials for your TV provider account. If you don’t know the required username and password, just get in touch with your TV service provider. Still, if you don’t get your TV provider in the list, then they might don't provide the support for the HBO GO on Amazon Fire TV.
7) Now, you will require to enter the activation code on the Activate a Device screen and then select Activate Device.
After following the steps mentioned above, you should get the “Success” message on both the computer and TV.