sandisk usb drive not showing in ipad pro 2020

To be recognised by iPadOS, the attached USB storage device must be formatted to FAT, FAT32, exFAT or APFS+ with a single partition. As the iPad has limited power capabilities, dependent upon the Storage Device, an external power source is often required.

If your iPad Pro has a Lightning port, you will need to use an Apple Lightning to USB3 Camera Adapter to directly connect USB devices to the iPad. This adapter has both a USB 3.0 Type-A connector and an additional Lightning port to supply power, from your charger, to both the iPad and connected device. The external charger must be rated at 12W or more.

If you have one of the newest iPad Pro models, with a USB-C connector, you may need to utilise a powered USB hub (i.e., it has its own source of power) - connecting both the iPad Pro and the storage device to ports on the hub.

I hope this is helpful.

Normally, you would use the Files app in iPadOS. Is that where you are looking?

I see that Apple carries this drive in its store, but it is shown as compatible with Macs, not iPads. The drive may draw too much power for the iPad.

Well, as I mentioned, the drive may require more power than the iPad Pro can supply. I don't know anything about the particular drive you have, like power requirement.

Some drives work OK if used through a powered hub or equivalent.