Unfortunately this is likely an account authentication issue between your Roku Pay-based subscription and the NFL's subscription database/bug in the app - you should report the issue to both Roku and the NFL.
Highlight the NFL app/Options (*)/Give us feedback/Could not login or authenticate
I signed up for nflgamepasses free 7 day trial using the roku interface and I discovered I was instantly instantly charged 9.99. Now I can't access the service from my TV because it informs me that I need to sign up for the service....crazy. So I see your solution to this is to remove the service and and then reinstall it after canceling the subscription, which seems like a must since removing it using my remote * key option doesn't appear as an option. So, 1. What happened to three trial?, and 2. If I sign up again will I be charged again for the " FREE TRIAL"? Totally triggering much angst. Please help.
How did you subscribe to the free trial? If you subscribed through the channel provider directly, you'll want to contact NFL Gamepass support directly to inquire further. Many channels on Roku are developed and maintained by the channel provider themselves. You can reach them here: https://support.nflgamepass.com/hc/en-gb
However, if you subscribed to the free trial through Roku Pay, please reach out to our support team directly here for your 'Account or billing' issue, here: https://support.roku.com/contactus. They will be able to further assist you.