How to update IOS version with data connectivity

Only if you have an iPhone 12 model or later with a 5G connection you can use over the 5G network.

Check if your carrier supports 5G.

See -> Use 5G with your iPhone - Apple Support

Are there any public WiFi hotspots you can use, such as in a library, a tea house, a shopping centre, an Apple Store, your cellular provider's store or service centre, etc.? It need not be your own home network.