Can I add data to a wifi iPad
I’m planning to buy an iPad but no data cellular
Question marked as
Not sure what you are asking.
A Wi-Fi only iPad cannot use cellular data in any way.
If you want to add cellular service to an iPad, it must be a Wi-Fi + Cellular model.
To add cellular service, you need to pay for a plan from your cellular / mobile service provider of choice.
If you mean something else, please clarify.