Restarting iPad

If iPad isn’t responding, do one of the following:

• 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 an iPad with Face ID: 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.

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.

Why not? What happens when you try to turn it on?

How are you trying to turn it on?

How did you turn it off exactly?

Try plugging it in to power and see if it comes back on.

Or follow LotusPilot's suggestion.

There is no reset button on an iPad. You reset it as explained in Lotuspilot's post.