iPad Pro Use with EHD

Start by downloading the rather excellent iPad User Guide for iPadOS from the Apple Bookstore. That will give provide a lot useful information about the new OS, its new gestures - and the many new features of iPadOS. For your specific question, the section describing the Files App will be of particular interest to you.

Hope you find this helpful.

Yes, you can use many (but not all) external USB storage devices with your iPad following update to iPadOS.

Depending upon your device, you will likely need either an adapter or a powered USB hub - this being necessary in most cases to provide adequate power to the external storage device. If your external HDD is self-powered by its own power supply, it is generally much simpler.

Power considerations aside, the external storage device must be “formatted” to use a supported filesystem.

Great I cant find anything on Apple's website about this . Is there a how to anywhere ?