As per https://www.virginmedia.com/help/tv/how-to-use-virgin-tv-go-app VM TVGo is not supported on Amazon devices.
Can I get Virgin TV Go on Firestick or Chromecast?
No, Virgin TV Go does not support Firestick or Chromecast.
Supported mobile devices
To use Virgin TV Go, your mobile or tablet will need to be:
Note: Virgin TV Go is not available on Amazon Fire devices.
Supported computers and browsers
So long as you have the latest version installed, Virgin TV Go is supported on the following systems and browsers:
Note: If you register a computer using a browser, you’ll need to use the same browser with Virgin TV Go. Using a different browser, clearing cookies or using incognito mode will be seen as a different device.
It is possible to sideload the TVGo app and other browers on Amazon devices (google search is your friend here) you may also need athird party app such as mousetoggle but TVGO still isn't supported on Amazon devices.