Your iPad2 is obsolete.
Apple ended update support for these models in September 2016. Your iPad cannot be updated to iOS 10 or later major versions of iOS, as the internal hardware does not meet the minimum technical requirements for new versions of iOS/iPadOS. This limitation cannot be bypassed; these are 32-bit architecture devices, whilst all recent versions of iOS/iPadOS are designed for 64-bit hardware platforms.
Consider that compatible Apps for your iPad are increasingly difficult to find - as App Developers have dropped all support for 32-bit devices and most for iOS versions preceding iOS11/12/13. As older versions of Apps are removed from the Apple App Store, you’ll not be able to (re)download or install them - which will severely limit any ongoing usefulness and utility of the iPad.
Your “buyer” is unlikely to be aware that the all iPad is now almost useless. Please do the decent thing - and simply responsibly recycle this obsolete device through an Apple Store. Anyone that acquires an obsolete device will be severely disappointed when they discover that the iPad has no utility or usefulness - and will be asking you to return their money.
