Regarding this the error, it is not related to game but with Google Play Store payments.
There are things which you can try to resolve this and the same we will list them down.

Request you to go sequentially with the Fixes

Fix 1: Clear Google Play Cache and Data with

  1. Open App Drawer.
  2. Find Google PlayStore and tap and hold that for 1 second.
  3. Click on (i) App Info.
  4. In the next window, click on Storage Usage.
  5. Now click on Clear Cache.
  6. You can also click on Clear Data, but you will have to log in again.

Once your corrupt cache is cleared, you can open your game and continue working on that to check whether the payment issue is fixed or not. If not, follow up with the next fix.

Fix 2: Switch to a Different Payment Method

Follow these steps to change your payment method in Google PlayStore.

  1. Open App Drawer and launch PlayStore.
  2. Now choose the item you want to purchase.
  3. Click on your current payment and then choose a different payment method.
  4. Complete your purchase and check whether you face the error

If you notice the error again, check your account balance.

Fix 3: Add Your Payment Details Again

Follow these easy steps to do the same:

  1. Open App Drawer and launch PlayStore.
  2. Now, tap on your profile picture.
  3. In the next window that opens, click on Payments & subscriptions.
  4. Now click on Payment methods
  5. If you have added any method previously, remove that by clicking on More Payment Settings below.
  6. Once removed, click on Add credit or debit card
  7. Enter your details accurately and click on Save.

Fix 4: Check For Notifications on PlayStore

As you are experiencing the error, you must have also got the notification from PlayStore.

Please make sure you check out the notification because usually, clicking the notification will have the necessary steps you need to follow if you want to fix the error. Follow these easy steps to open the notification and check this:

  1. Open Google PlayStore.
  2. On the top right corner, you will see a bell-like icon if you have ever experienced.
  3. If not, click on your Profile Picture and tap on Notifications and Offers.
  4. Now check what PlayStore says to fix the error code

In case your issue still doesn't gets resolved then the last resort will be to create a support question on Google.

Please feel free to let us know for further questions and we would be more than happy to help