My touchscreen feature is not functional. Also I cannot perform a hard power off.

As a first step, connect your iPad to its Power Adapter; whist still connected to external power, try a forced-restart:

• On an iPad with a Home button: Press and hold the top button and the Home button at the same time. When the Apple logo appears, release both buttons.
• On other iPad models: Press and quickly release the volume up button, press and quickly release the volume down button, then press and hold the top button. When the Apple logo appears, release the button.

Note:  If iPad still doesn’t turn on, or if it gets stuck during start up, see the Apple Support article If your iPhone, iPad, or iPod touch won’t turn on or is frozen. Or if your iPad isn’t working correctly after you restart it, see the iPad Support website.

If you continue to experience difficulties, you might be best advised to seek assistance directly from from Apple Support. You can contact the Support Team using the Get Support link at top-right of this page. Alternatively, if you have another device, you can initiate and manage support cases using the excellent Apple Support App. If not already installed on your iPad, the App can be downloaded from the App Store:

https://apps.apple.com/gb/app/apple-support/id1130498044

You might also visit the Genius Bar at your local Apple Store or Apple Authorised Service Provider (AASP) - where the technicians will be able to test and assess your iPad:

Genius Bar Reservation and Apple Support Options - Apple

If the steps in the Article you came from did not resolve your problems,

then you need to make an appointment at the nearest Apple location to have your iPhone evaluated for free.

Once the diagnostics are complete, the staff will explain your options.

Make a Genius Bar Reservation

https://www.apple.com/retail/geniusbar/