Call the company that made your harp and ask for advice. They ship harps worldwide and could best advise you.
I was told when I shipped my harp in the US to put a big up arrow on the case and fragile sticker. I was also told to write in the shipping instructions and put a sign on the case that said, “Do not stack or use forklift.” Of course, don’t assume anyone can or will read instructions.
Also check on your insurance policy and ask the harp company for advice on that, too.