This is an Apple thing. Accounts made on IOS devices are locked to IOS devices unfortunately. The reverse is not true luckily so when you make an account on Android you will also be able to use it on an IOS device.
See this help page for instructions of what to do in your case (the first NOTE), or do as above .
https://support.fongo.com/hc/en-us/arti ... e-devices-