captivate 8 LMS calls - send/retrieve data

Please help!

I am creating elearning using Captivate 8 and publishing in html 5.

How do you send user variables / data to the LMS from captivate 8?

Have tried following from the JavaScript window in Cp8 but no luck:

to send data:

document.getElementById('Captivate').SCORM_CallLMSSetValue("cmi.core.lesson_status", "Passed");

to retrieve data:

var str = document.getElementById('Captivate').SCORM_CallLMSGetValue("cmi.core.lesson_status");

display retrieved data in captivate: window.cpAPIInterface.setVariableValue("lessonStatus", str );

captivate shows result as: 0

Any help would be appreciated

Thanks!