IPad Pro won’t charge

See >>> If your iPad won't charge – Apple Support

Does it say “Not Charging” at the battery bar? If it does, then that means you need a new charger. If it doesn’t, make sure that it is fully plugged in. If it is fully plugged in, but it says nothing, you still would need a new charger. Make sure that it is an iPad charger ONLY supported by Apple. If the problem still persists, then Get Support