ClosedXML is a .NET library for reading, manipulating and writing Excel 2007+ (.xlsx, .xlsm) files. It aims to provide an intuitive and user-friendly interface to dealing with the underlying OpenXML API.
$ dotnet add package DocumentPartner.ClosedXMLClosedXML allows you to create Excel files without the Excel application.
Example:
using (var workbook = new XLWorkbook())
{
var worksheet = workbook.Worksheets.Add("Sample Sheet");
worksheet.Cell("A1").Value = "Hello World!";
worksheet.Cell("A2").FormulaA1 = "=MID(A1, 7, 5)";
workbook.SaveAs("HelloWorld.xlsx");
}