I don't know of a way to put Octoprint behind the Klipper. You would need to put octoprint on the Nebula tablet that comes with the KE. However, the way Klipper is installed on the Nebula pad makes it difficult to do unless you really know what you are doing.
I do know that the same guy, Destinal, is working on a new image for the Nebula pad that would remove the "CrealityOS" and use Debian(if I recall correctly) which will allow you to easily install other apps like Octoprint.