How do I ad personal hotspot on my iPad

See >>> How to set up a Personal Hotspot on your iPhone or iPad - Apple Support

If your iPad does not have a SIM slot, then you have a WiFi Only model of iPad. WiFi Only models do not have any Cellular capabilities. Whilst a WiFi Only iPad cannot be transformed into a WiFi+Cellular model, you can use the hotspot feature of a mobile phone - or a Cellular Broadband Router (often known as a MiFi Router) - to access Cellular networks.

Is your iPad a Wi-Fi and Cellular model?

If yes, do you have a active SIM in your iPad?

If no, you can't.