Not being able to purchase coins/packages could be related to many reasons.

• It is better to start by checking if there are any restrictions on the device. You can check out the following link:

Require a password or authentication for purchases

• Your internet connection should be stable to make a purchase. We suggest you use Wi-Fi or at least a 3G/4G/LTE connection while purchasing any package.

• There might be temporary problems with the store where the game was downloaded from. All in-app purchases are made through the App Store/Google Play and there is a chance that the store is not able to respond to in-app purchases. You can restart your device and try again.

• Your payment information might be incorrect that's why you are not able to complete in-app purchases. To get more information:

Fix payment issues on your account

Hope this helps!