Restore iPad to factory settings
You can use a Mac or Windows PC to erase all data and settings from your iPad, restore iPad to factory settings, and install the latest version of iPadOS.
Important: Restoring your iPad to its factory settings erases all your data and settings. However, before iPad is erased, you have the option to back up your iPad. If you make a backup, you can use the backup to restore your data and settings on your iPad or on a new device. See Restore iPad from a computer backup.
Do one of the following:
In the Finder sidebar on your Mac: Select your iPad, click General at the top of the window, then click Restore iPad.
Note: To use the Finder to restore iPad to factory settings, macOS Catalina is required. With earlier versions of macOS, use iTunes to restore iPad.
In the iTunes app on a Windows PC: Click the iPad button near the top left of the iTunes window, click Summary, then click Restore iPad.
Follow the onscreen instructions.
See the Apple Support article If you can’t update or restore your iPhone, iPad, or iPod touch.