Greetings @Seiber1730, and a warm welcome to the Roku Community!
We understand you're having trouble accessing your Discovery Plus channel, and we're here to help you.
Please be informed that if you have subscribed directly through Roku, you can only use this subscription through Roku, and it will not be accessible on any other streaming device. To access the channel, you must sign in to your Roku device using the email address associated with your subscription.
To check the email address associated with your Roku device, please follow these steps: go to Settings > System > About. You'll find your email address there.
If you need any further assistance, please let us know. We're always here to help!
Thanks,
Jharra
Jharra Q.
Roku Community Moderator