I really have no idea. If you upload the photo to the portal it’ll tell you if you can use it or not. But if you can’t use it, there are plenty of artists on the forums who’d be willing to make cover art for you!
In the Content Guidelines, it states that “No celebrity images or illustrated likenesses are allowed on backgrounds, overlays or story cards.” This most likely extends to covers as well, but like Penny2 suggested, go ahead and submit it for review. The review team will know whether or no it’s allowed.