How do I find screen resolution for iPad model MY2HNF/A?

The A2229 is a fourth generation iPad Pro 12.9" - having a 2732 x 2048-pixel resolution at 264 pixels per inch (ppi).

Here you will find its full specifications:

iPad Pro 12.9-inch (4th generation) - Technical Specifications - Apple Support

You'll need to provide information as to the iPad model in which you have specific interest. You can find your iPad model name here:

Settings > About > Model Name

The generic model identifier is not immediately obvious. Tap the MY2HNF/A field to display the "A" number - as this more accurately identifies your iPad model. The number that you quote is Apple's internal order number.

Go to settings>display and brightness>tap view to see your screen resolution

The A2221 model identifier is not an iPad - but corresponds with an iPhone 11.