How can I delete a sandbox?
It should be under course settings if it is not I would contact your Canvas admin and ask for it to be deleted. It would be helpful to them to include the url to your course settings page of the Sandbox you want deleted.
Some institutes don't have this enabled for user's to delete courses and like Brian said best bet is to contact your Canvas admin and have them delete it for you or another option you might have under course settings is to "Conclude this Course" which will close it out and drop it under Past Enrollments.
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