external drive with ipad

See -> Connect external storage devices to iPhone

Connect external storage devices to iPhone – Apple Support (UK)

See also -> SanDisk iXpand-flashdrive Go 

SanDisk 64 GB iXpand Flash Drive Go - Apple

SanDisk iXpand Drive app - App Store

https://apps.apple.com/us/app/sandisk-ixpand-drive/id1079870681

It is a little hard to help/advise you when you provide little to NO useful information about your iPad.

Here are my questions to you.

Can you, please, confirm what year and model iPad do you have/own?

The “A” model number can be found on the aluminium back of your iPad, in very small print, right under the larger bold print “iPad” on the back of the iPad.

What iOS/iPadOS version is this iPad, currently, running?

What is the rated, internal data storage space/capacity of your iPad model and how much of this free, internal data storage capacity is left inside of your iPad model?

All of that additional info can be found in the Settings app, General settings panel, About.

Please try to make an attempt to answer all questions asked.

If you own an iPad with an Apple Lightnng connection port, your external drive options and setup are limited and such external drives may need the use of external power to both power the iPad AND the external drive.

Thank You.