when export data to excel error excel file not readable cont

problem

Note main issue related to type script because i can get data but i cannot display on Excel when export

I work on angular 7 app I click button to export data from database to Excel it create file when i open it

give me error ( excel file not readable content ) why and how to solve issue this my problem .

I pass parameter value to stored procedure and execute it and get result from database then export it to excel .

Main issue why not export data to excel and how to make export correct this actually what i need .

web API

[HttpPost]
public IActionResult GetDataBasedOnDynamicSp([FromBody] dynamic DataObjectRevision)
{
string SpName = DataObjectRevision[0].downLoadProcedureName;
string revid = DataObjectRevision[0].revisionID;
var PostRevision = _reportservice.GetSpByRevisionId(revid, SpName);
return Ok(PostRevision);
}

Angular service.ts

}

component.ts

public exportJsonAsExcelFile(json: any[], excelFileName: string): void {
const worksheet: XLSX.WorkSheet = XLSX.utils.json_to_sheet(json);
const workbook: XLSX.WorkBook = { Sheets: { 'data': worksheet }, SheetNames: ['data'] };
const excelBuffer: any = XLSX.write(workbook, { bookType: 'xlsx', type: 'array' });
this.saveAsExcelFile(excelBuffer, excelFileName);
}
private saveAsExcelFile(buffer: any, fileName: string): void {
const data: Blob = new Blob([buffer], { type: EXCEL_TYPE });
FileSaver.saveAs(data, fileName + new Date().getTime() + EXCEL_EXTENSION);
}
getDataByRevision(RevId : any)
{
this.ReportData.forEach(function(e) { e.revisionID=RevId });
this._displayreport.GetSpByRevisionId(this.ReportData).subscribe(data=>{
console.log(data)
this.exportJsonAsExcelFile(this.ReportData ,'datarevision');
});
}

component .html

Data below is result of API and angular above and this data Exactly must show on Excel But this Not Done