Your hitch is likely only rated for 500 pounds of tongue weight without a WDH. If, and that's a big if, your tongue weight is really only 540 pounds I would probably try it. But, I have been towing all manner of trailers for years. If you've never towed anything before I wouldn't recommend it.
Not only should you probably get a WDH, you need to (or have someone) set it up correctly. This may involve doing some practice towing around locally before taking off across the country. Don't expect to put the hitch on in the parking lot of the store you bought it from and then leave for several states away. It doesn't work that way.