Adding to what was already said. It depends on what caused Touch ID to stop working in the first place. The only way to replace the home button and keep Touch ID intact is to have the iPad serviced by Apple. In the case of iPads, Apple does not repair the devices as a part of service. They replace them at “out of warranty replacement” cost. Which essentially means swapping out the non functional unit for functional refurbished one (which would contain new battery and any of the externally visible parts).
Touch ID itself may be able to be repaired depending on your level of skill as a technician and the specific fault. If there is a tear in the cable, you can repair he cable by splicing the severed connections together with soldered on jumper wires. But the cable is small and fiddly and it’s difficult to make a repair that will hold up over time.