Scope

Error: "Input param `subscriptions.trial_end_action` can be sent only when the feature Trial End Action is enabled." 

Summary

End of trial actions 
Trial period completion can result in subscription activations or cancellations. This setup defaults to how you want to handle trial completion scenarios. You can also set these defaults as mandatory, and prevent overriding by locking them.

Solution

This feature is not available by default and it has to be enabled from the back-end. You can reach out to support@chargebee.com to enable this feature.

Once you enable the feature, you can set the site-level configuration for the end of trial period by navigating to Configure Chargebee > Subscription trial management > End of trial actions

To override the End of Trial action for a Subscription, click on ellipses (three dots) and enable the toggle for 'Allow overriding via Chargebee interface'