Help & troubleshooting for channels on your Roku device, including adding/removing channels, logging in to, authenticating, or activating a channel, channel-specific playback issues, assistance contacting channel publishers to report issues, and adjusting channel-specific settings.
Re: How do I subscribe to NFL live TV from Roku account?
I'm not familiar with that channel, but there's only a handful of channels that you can subscribe to through Roku. For the remainder, you have to go straight to the provider.
Checking the channel store I don't see a channel called NFL Live TV. I'm assuming you mean the regular NFL channel. This also list NFL Sunday Ticket. It appears the latter is restricted to DirecTV subscribers.
For the regular NFL channel, it appears you need to subscribe via the NFL web site. However, it too appears to require a TV provider, such as a satellite or cable provider, as well as YouTube TV or Sling for streaming providers.
Dan Roku Stick (3600), Ultra (4640), Ultra (4670), Premiere (3920), Insignia 720p Roku TV, Sharp 4K Roku TV, Nvidia Shield, Windows 10 Pro x64 running Serviio and Plex on a wired Gigabit network.