Export data to excel in ASP.Net Core

Sometimes it is more useful to export data into OpenXML format - xlsx than to CSV - especially in the case when multiple data collections should be positioned in the same file. 
The other case is when basic esthetics is required, so it is easier to examine the contents.

This article explains how using the ClosedXML wrapper we can export data in .Net Core to xlsx:

http://hpblogs.com/blogs/export-to-excel-in-asp-net-core-3-1/5