"Unable to purchase" when trying to install a free App on iPad model A1432

Outdated iPad no longer meets the requirements for many apps.

Most apps requires iPadOS 13 or later, Facebook requires iPsdOS 13.4 or later.

Considering a newer type of iPad?

Read this before you buy a newer iPad.

Apple Store -> iPhone - Buying iPhone - Apple

Apple Certified Refurbished -> Refurbished iPhone Deals - Apple

You have an obsolate iPad from 2012, it can't be updated beyond iOS 9.3.5.

Gmail requires iPadOS 14.0 or later.