how to connect a locked out ipad to itunes?

The link provided above is not the right link to help you.

Follow the directions in this link to get back in a device for a forgotten passcode: If you forgot the passcode for your iPhone, iPad, or iPod touch, or your device is disabled - Apple Support

Are you trying to use recovery mode? Here’s how: https://support.apple.com/en-us/HT201263

this will reset your iPad, but it’s your best option if you don’t know the password.

He doesn't remember his Passcode.