A1652 iPad Pro Battery

If your iPad won't charge - Apple Support

If you have them, try other known good charge cables and Apple power/charging blocks to make sure tge ones you ard currently using are not faulty in some way.

Also, plug the iPad into power and try a hard reset of your iPad by holding down both the Home and sleep/wake buttons simultaneously until your iPad goes to black and restarts with Apple logo, then release the buttons.