Some one tell

If you are not using the original charger it can be normal, I would recommend to buy the original 20W charger. If you are using the original make sure it's 20W(the iPad normally charges with that type of charger). Sometimes when the iPad is very low on battery and you have that type of charger it can generate heat due to the fast charging but I wouldn't worry to much about it.

It is completely normal for a Power Adapter to run warm while charging the iPad - in particular if the iPad is being used while charging.

While the Power Adapter and/or iPad can be expected to become very warm in certain circumstances, neither should ever become uncomfortably hot to hold.