This article will teach you how to export any list into Excel in C# using the ClosedXML library. Steps to complete Create the data model with dummy data that we'll export into Excel. Create ExportExcel interface methods that accept any type of List (using IEnumerable<T> ) and a Dictionary List and export a byte array. Create extension methods and convert the provided data into rows and columns (using DataTable ). Create a service class that implements the interface methods and export the data table into a Memory Stream (byte array) using ClosedXML . Create one API endpoint that exports data in memory into Excel. Create another endpoint that exports incoming (custom) request data into Excel. Wire up dependencies.…