First, do you have multiple Roku devices? It's possible that you've inadvertently set up more than one Roku account. If you do, check the email address displayed on each device under Settings->System->About.
Can you log in at https://www.peacocktv.com/ ? Try the "Forgot password" option if necessary.
Roku Community Streaming Expert
Help others find this answer and click "Accept as Solution."
If you appreciate my answer, maybe give me a Kudo.
I am not a Roku employee.