As your iPad is already in recovery mode, there is no longer a bootable Operating System - and as such, you'll not be able to restart the iPad to a running state until the iPad has been restored to factory settings. This will process will install a fresh copy of the most recent version of iPadOS that is supported by your iPad:
Restore your iPhone, iPad, or iPod to factory settings using a computer - Apple Support
To do so, you will need access to either a Windows PC (with iTunes for Windows installed - or the more recent Apple Devices App) or a Mac (with iTunes or Finder - as appropriate for the installed version of MacOS). Ensure that your installed version of iTunes has been updated to the most recent version; the essential device drivers are included.
Download and use iTunes for Windows – Apple Support
Update to the latest version of iTunes – Apple Support
Update software on iPhone, iPad or iPod touch in iTunes on PC - Apple Support
Update your iPhone, iPad, or iPod touch with the Finder - Apple Support
Apple Devices App (Windows PC):
https://apps.microsoft.com/detail/9np83lwlpz9k?hl=en-ms&gl=MS
If you iPad is not recognised when connected to your computer, try using a different USB port; if your computer has both USB-C and USB Type-A ports, try using the USB Type-A port of the computer.
(*) If you don’t have access to a suitable computer of your own, that of a helpful friend or family member will suffice. Alternatively, the technicians at the Genius Bar of your local Apple Store or Apple Authorised Service Provider (AASP) will be delighted to assist.
Genius Bar Reservation and Apple Support Options - Apple
If you have tried to restore your iPad without success - and you have presumably enlisted help from Apple in your country - you may have exhausted your available options. You might alternatively try to seek assistance assistance directly from Apple Support. You can contact the Support Team using the Support link at top-right or bottom-left of this page.
Alternatively, you can initiate and manage your support cases from Apple devices using the excellent Apple Support App. If not already installed, the App can be downloaded from the App Store:
https://apps.apple.com/app/apple-support/id1130498044
