Spot on ipad

Presumably this is a photo of the iPad screen. Do you have a screen protector fitted?

If so, remove the screen protector from the screen - and reappraise what you see. If the spot remains on the screen, the only remedy will be replacement.

For practical purposes, in lieu of repairing and returning your own iPad, Apple usually exchange the iPad for a renewed/refurbished iPad of the same model and specification. The cost of the exchange is the same as would otherwise be charged for repair. Unless you have benefit of an active AppleCare plan, an out-of-warranty repair while expensive will be somewhat less than the cost of a replacement iPad.

As for out-of-warranty repair costs, Apple offers a fixed-price price repair. You can verify eligibility and cost for your region/country here:

iPad Repair & Service - Apple Support

If you have an active AppleCare+ plan, the cost of repair is reduced to a small excess/deductible fee.

There is no scale in the photo. Roughly how big is this spot.

Hard to tell but there appears to be scratches associated with the spot. That could indicate it is the result of some form of impact damage.