If you still see the Restore screen after you restart, you need to reinstall iOS or iPadOS:

On your Mac, make sure that you’ve installed the latest software updates (including iTunes if you have MacOS Mojave or earlier). Or on your Windows PC, make sure that you’ve installed the latest version of iTunes. Make sure that your device is still connected to your computer. You should see this message: "There's a problem with the [your device name] that requires it to be updated or restored." Click Update (not Restore) to reinstall iOS or iPadOS and keep your personal data. Don't disconnect your device from your computer until the update finishes.