why search string 'Text6=''locations''' not work from web API and give excption but it work from sql ?

public DataTable GetReportDetailsSearch(string ReportID, string FromDate, string ToDate, string SearchString)
      {
          List<SqlParameter> param = new List<SqlParameter>()
          {
              new SqlParameter("@ReportID", ReportID),
              new SqlParameter("@ReportDateFrom", FromDate),
              new SqlParameter("@ReportDateTo", ToDate),
              new SqlParameter("@SearchString",SearchString),

          };

  DataTable ReportDetailsSearch = SQLDAL.ReturnDataTableByProcedure("sp_ReportDetailsGetALL", param);
          return ReportDetailsSearch;
      }



[Route("ReportDetailsSearch")]
       [HttpPost]
       public IActionResult GetSearchedData([FromBody] dynamic DataObjectSearch)
       {

           try
           {
               string ReportId = DataObjectSearch.reportID;
               string FromDate = DataObjectSearch.startdate;
               string StartDate = FromDate.Substring(0, 10);
               string todate = DataObjectSearch.enddate;
               string EndDate = todate.Substring(0, 10);
               string Searchdata = DataObjectSearch.searchstring;

               var PostSearch = _reportservice.GetReportDetailsSearch(ReportId, StartDate, EndDate, Searchdata);

               return Ok(PostSearch);


       }

When execute web api search string added to it double quotes why and how to solve issue ?

I work on web api asp.net core 2.2 I face this error

An expression of non-boolean type specified in a context where a condition is expected, near 'and'.

procedure work from SQL success as below

exec [dbo].[sp_ReportDetailsGetALL] "2028","2020-05-03","2020-05-11", 'Text6=''locations'''

exactly issue on the following line

'Text6=''locations'''

not work if as below

"'Text6=''MFG'''"

on web api i think it add double quotes on start and end so that it not work

json i passed to web api as following :

{ "startdate": "2020-05-03T22:00:00Z", "enddate": "2020-05-11T22:00:00Z", "searchstring": "'Text6=''MFG'''", "reportID": "2028" 
} 

procedure getreportdetail as following :

declare @ColumnName Nvarchar(max) = (SELECT 'select ' + STUFF((SELECT ',' + 'Text'+CONVERT(varchar(20),ReportHeaderIndex) + ' '+ '['+ReportHeader +']' 
FROM ReportHeaders where ReportID=@ReportID order by ReportHeaderIndex 
FOR XML PATH('')) ,1,1,'') + ' , convert(nvarchar(20),[ReportDate]) ReportDate From ReportDetails R where ReportDate >= ''' +@ReportDateFrom+''' and ReportDate <= '''+ @ReportDateTo +''' and R.ReportID =' + @ReportID + ' and '+@SearchString+' and IsHistory=0 order by reportdate desc ' + @SortingColumns AS Txt ) 
exec (@ColumnName)