I am trying to generate QR code using RDLC and Asp.net Core but getting below error

Question

I'm using ASP.net core 5.0 and RDLC Microsoft Report Builder.

My code:

int extension = 1;
string mimtype = $"";
var path = $"{_webHostEnvironment.WebRootPath}\\Report\\prescription.rdl";
var prescription = await _prescriptionRepo.GetPriscriptionById(id);
var imagae = GenerateQrCode("sfsdf");
var pres = _mapper.Map<GetPrescriptionForReport>(prescription);
Dictionary<string, string> parameter = new Dictionary<string, string>
{
    { "patientname", $"{prescription.Patient.FirstName} {prescription.Patient.LastName}" },
    { "prescriptionid", $"{prescription.PatientId}" },
    { "advice", $"{prescription.Note}" },
    { "doctorname", $"{prescription.DoctorFirstName} {prescription.DoctorLastName}" },
    {"image", imagae}
};        
LocalReport localReport = new LocalReport(path);
localReport.AddDataSource("DataSet1", pres.MedicineForPrescription); 
var result = localReport.Execute(RenderType.Pdf, extension, parameter, mimtype);
var foo = File(result.MainStream, "application/pdf");
foo.FileDownloadName = $"{prescription.PatientId}-{prescription.Patient.FirstName} {prescription.Patient.LastName}.pdf";
return foo;

and

private string GenerateQrCode(string qrmsg)
{
    QRCoder.QRCodeGenerator qRCodeGenerator = new QRCoder.QRCodeGenerator();
    QRCoder.QRCodeData qRCodeData = qRCodeGenerator.CreateQrCode(qrmsg, QRCoder.QRCodeGenerator.ECCLevel.Q);
    QRCoder.QRCode qRCode = new QRCoder.QRCode(qRCodeData);
    Bitmap bmp = qRCode.GetGraphic(5);
    using (Bitmap bitMap = qRCode.GetGraphic(5))
    {
        using (MemoryStream ms = new MemoryStream())
        {
            bitMap.Save(ms,ImageFormat.Png);
            var byteImage = Convert.ToBase64String(ms.ToArray());
            return byteImage;
        }
    }
}

In RDLC Report: Add parameters Name : image

then

Insert> Image > Parameter > image

when I try to load the report

I'm getting the error

AspNetCore.Reporting.LocalProcessingException: An error occurred during local report processing.;The definition of the report 'I:\DotplusWeb\HospitalAPI\HospitalAPI\wwwwroot\Report\prescription.rdl' is invalid. The Value expression for the image ‘image’ contains an error: [BC30654] 'Return' statement in a Function, Get, or Operator must return a value. ---> AspNetCore.Reporting.DefinitionInvalidException: The definition of the report 'I:\DotplusWeb\HospitalAPI\HospitalAPI\wwwwroot\Report\prescription.rdl' is invalid. The Value expression for the image ‘image’ contains an error: [BC30654] 'Return' statement in a Function, Get, or Operator must return a value. ---> AspNetCore.ReportingServices.ReportProcessing.ReportPublishingException: The Value expression for the image ‘image’ contains an error: [BC30654] 'Return' statement in a Function, Get, or Operator must return a value.