How to make use of DataTables in .net core Application?

I am trying to import Excel to .net core web application. Somehow able to import excelworksheet successfully. 

When I try to copy them to a datatable, datatable objects are unable to create.

i.e Unable to get all the datatable methods and variables in .net core, even after using System.Data.

When I press F12 on the DataTable Class, it shows nothing.

         public class Datatable

         {  }

How to make use of DataTables in .net core to store data in the form of rows and columns?

Solutions Tried:

Used Using System.Data Namespace it is not working,

Installed DataTables.AspNet.Core NuGet Package, still not working.....