Is there ability to sign in directly to NFL network? Direct subscription from NFL network but seems most NFL network integration is based on only 3rd party logins.
Are you asking to get access without a tv provider subscription?
As in with paying for subscription via NFL Network directly. Not through a 3rd party provider.
Channels DVR seems to only support logins that use the TVEverywhere framework. So no, it wouldn't support a standalone subscription.
Is NFL Network currently selling standalone subs in the US? I couldn't find anything about it on their site.
NFL game pass $5 a month
Secondary logins (separate from and/or in addition to) like that NFL option, or MLB.tv, are not compatible with Channels. Only those networks which participate in the TV Everywhere SSO ecosystem and that have a live linear stream on their website will work directly within Channels.
At least in the case of MLB.tv, this homebrew docker add-on did the trick for many of us this season: MLB.TV for Channels