Can't Purchase Subscription through In App Purchase

If you get an error message when trying to purchase an in app purchase through iCertifi like this:

and you are connected to a network connection.  Check you have not restricted in app purchases in Settings. Settings>General>Restrictions>Allowed Content: Is In-app purchases on/off?  Make sure this switch is set to On

If you still can't make a purchase please contact Apple https://support.apple.com/en-gb/contact