I think I understand. You just started the app without configuring it, right?
On a PC android emulator, hit the F1 button, on an android go to the top right corner for the 3 dot menu, or use your menu button, and select Settings, and click on Portal to edit. Change the MAC that you will see on the first page of the settings, and exit out of the application. Start it, and you should be up and running if you entered a valid mac. There might be some other configuration for the video player depending on your install.
Thanks dara. If that's the case then it's not possible to do this on the Fire TV and perhaps some other Android-based devices as it's not possible to access settings due to the limited options given to users. Here's the options that I get for the app:
There's no option to configure the settings for the app just like any other app on the Fire TV. An in-app settings page would have been ideal but I'm not too fussed as I prefer to use Kodi due to its integration with the rest of my media.