If your customers experience “ !!! “(exclamation) symbols when they try to enter their card details at their checkout page this could be for reasons if the Google Maps API key is expired, invalid or not created. 

A quick fix for this issue is to turn off your address autocomplete by navigating to Settings > Configure Chargebee > Checkout & Self-Serve Portal > Advanced Settings and turn off "Autocomplete addresses"

To permanently fix this, you need you to ensure that your API key is updated in Chargebee. To do so you can contact the support team by sharing the google maps API credentials in a secured document. 

If you have recently enabled custom domain ensure to update your API keys.

Here’s how to create a Google Maps API Key.

Note: This error message is not caused because of the custom domain being enabled for your account. Disabling custom domain will break your existing integration. 

Related Articles and Documentation

How to request for the Custom Domain feature? 

Google Recaptcha for custom domain