Ipad mini

No. Internal hardware, such as Cellular or internal storage, cannot be added or upgraded. The internal hardware is fixed for the life of the device.

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.

No.

There is NO cellular data service hardware inside of a WiFi ONLY iPad.

If you need both WiFi AND cellular data service in an iPad, you need to purchase a WiFi AND cellular data iPad model.

If you own a cellular smart phone the has a WiFi hotspot feature, you can pair a WiFi ONLY iPad to a smart phone with this feature to get cellular connectivity to your iPad in this manner.

Best of Luck to You!