How do I delete disney+ from my roku account after its canceled

What do you mean by, "delete it off my roku account"?  Do you mean remove the channel/app from your Home Screen?  If so, you should be able to highlight it on the Home Screen, press * on your remote, and choose "Remove whatever".  If you see "Manage subscription" instead of "Remove ...", then you may have to wait until your subscription expires.  Canceling a subscription only keeps it from auto-renewing.  You still have access until the end of the original subscription period.

If you mean something else, please give more details.