Hi @funktologist,
Welcome, and thanks for posting here in the Roku Community!
We understand that you're having difficulty paying with your subscription.
If you are asked to update your payment method while trying to subscribe to a specific channel, it may indicate that the payment method you have on file has expired or needs to be updated.
This prompt is typically a security measure to ensure that the payment information associated with your subscription is current and valid. You have the option to update your payment method either through your Roku Account on the web or directly through your Roku Devices.
For more comprehensive details on how to update your Payment Method, visit this article: How to update your Roku payment method.
Please let us know if there is anything else we can do to assist you.
Warm regards,
Emman
Emmanuel-D.
Roku Community Moderator