ensure that you set the Accept header value to a JSON media type. For example, application/json.

Data action returns “Invalid JSON” even when the body is valid JSON.
Transfer-Encoding: chunked -> Transfer-Encoding: buffered

This article applies to the Adobe, AWS Lambda, Genesys Cloud, Google, Microsoft Dynamics 365, Salesforce, web services, and Zendesk data actions integrations.

It's compatible with the translation map in Genesys Cloud data action.