"error": "Error during virtual endpoint execution. Contact Administrator for more details."

You should be able to messages in the gateway logs. You might have to enable debug mode if I remember correctly.

Errors in the logs most of the times means a syntax error. So my guess is it doesn’t like

Body: JSON.parse(response),

For the first error you might want to add the Code field in the responseObject to verify. I know the value of Body needs to be a string so maybe using a static string to debug might help find the cause.