Fifth Generation iPad Model A1823

If your iPhone or iPod touch won't charge - Apple Support

Remove any debris from the charging port on the bottom of your device, then firmly plug your charging cable into your device. If the charging port is damaged, your device probably needs service.

Be particularly careful when probing the port. Be gentle, avoiding damage to the delicate pins. Use only a non metallic item, such as wooden toothpick.

Why not? What happens when you try to insert the charger cable? Is something blocking the port?

Is the port mis-shapen in some way?

Are you using the charger cable that came with the iPad, or a different one? If a different one, which make and model?