NVPCallerServices caller = null;
caller = new NVPCallerServices();
APIProfile profile = null;
profile = ProfileFactory.createSignatureAPIProfile();
WARNING: Do not embed plaintext credentials in your application code.
Doing so is insecure and against best practices.
Your API credentials must be handled securely. Please consider
encrypting them for use in any production environment, and ensure
that only authorized individuals may view or modify them.
// Set up your API credentials, PayPal end point, API operation and version.