Additional storage for iPad pro

You can connect pretty much any external drive to the iPad as long as its formatted as Fat32, exFat, HFS+ or APFS. You can use a Lightning to USB adapter: link-> https://www.apple.com/shop/product/MD821AM/A/lightning-to-usb-camera-adapter

You will have to manually move content off of the iPad and onto the hard drive however, the iPad will not use the drive as added storage automatically.

Here's a small list to get you started. If you set it up for an external backup, you can automate to see it when you connect it using Apple's backup program. You can adjust the storage results in the search link, on the left, by the type of ipad you specifically have. I suggested these because they are very small and not cumbersome to tote with the iPad .

https://www.apple.com/shop/accessories/all/storage?page=1&f=ipadpro129_5gen2021&fh=40aa%2Bad97f7