I cannot buy or download a dictionary - I get an ‘In-app purchases are not allowed’ pop-up.

If you are receiving a pop-up along the lines of ‘In-app purchases are not allowed’ when you try to buy or download a dictionary, this is most likely because you have disabled in-app purchases in your device’s settings.

To enable in-app purchases (so to be able to buy or download a dictionary), please go to Settings > General > Restrictions and scroll down to In-App Purchases. Enable this option by toggling the switch to green. More information is available on this Apple support page.