External hard drive

Your HDD must only have a single data partition - and be formatted as FAT32 or exFAT.

Multiple data partitions and Microsoft proprietary formats (such as NTFS) are not support by iPadOS. Apple APFS and HFS+ formats are supported by your iPad, but not by your PC.

You must also ensure that the HDD has an adequate source of power other than the iPad. If the HDD does not have an integral power supply, you must use a powered USB hub. The iPad alone cannot supply sufficient power to high-power USB devices such as HDD drives.

With the HDD correctly partitioned and formatted, you’ll be able to export Photos from your Camera Roll to external storage - and/or copy files using the native Files App or other third-part File Manager Apps.

I hope you find this to be helpful in providing some useful clarity.

Some USB HDD devices have an external power input - most don’t, instead relying upon the USB bus to provide the necessary power. As such, a powered USB hub, to which you connect both the USB HDD and iPad, is by far the best and most flexible option.

You could purchase one of the drives from the Apple store and reformat

it to your preferred file system.