Export embedded Q&A results to PDF

Hi,

I'm using Q&A Embedded in my web application, by following below link  

• https://docs.microsoft.com/en-us/power-bi/developer/embedded/qanda

Now, the requirement is to export Q&A results through API.

I've been tried below API but I couldn't take any export getting below error.

"status": "Failed",
    "error": {
        "code": "ExportReport_UnknownError",
        "message": "RootActivityId(a6860d1e-5910-46c5-adc1-504b098f76b2): Exporting the requested report failed due to an unknown error. Please try again later.",
        "details": []
    },

but in the case of a simple report, the same API calls/code is working fine. But not in the case of Q&A.

Please me to sort it out.

Thanks.