April - last edited April
Hi, maybe this will help. Try the purchase from the original device for now. Sometimes it takes a bit for it to work when you switch devices. It’s the device not the game that is the problem . Just wait a few days and try again. Just purchase and then when it is completed on the original device simply log back on, on the iPad, and it will be there. -Apache
Just to expand on @Apache512 answer.
This can happen if you are trying to buy something on a device that the Iron Force account you are using was not created on. If you still have the device your Iron Force account was created on you should be able to make purchases without any issues.