See newer version documentation - Copyleaks V3 API .
You can test the integration with Copyleaks API for free using the sandbox mode. You will be able to submit content to scan and get back mock results, simulating the way Copyleaks will work.
To turn the sandbox mode on, add the http-header copyleaks-sandbox-mode to your calls. No matter what the value is.
Unlike the scans in production, the sandbox scans have a short lifespan and will expire after 24 hours and will be no longer avialble.