Thanks for the post.
Can you please clarify the issue you are experiencing? Can you please provide a screenshot of the issue you are seeing?
For more information about how to update your PIN, visit our Support page here: How do I create or update the PIN for my Roku account?
Please keep us posted.
You set a PIN on your Roku account by logging into it on https://my.roku.com, using the email address associated with your account as the login name.
Make sure your Roku is connected to this same account. When you go to Settings > System > About on your Roku does it show the same email address?
Thanks for the update.
What Roku model device are you trying to add the Youtube TV channel to?
With more information we will be able to assist you further.
If you bought it used did you factory reset it and link it to your own Roku account? Whose email address is shown under Settings->About?