how to insert postgresql table using C# dataTable & postgresql COPY, without EF core

Question

I want to insert into postgresql(12.9) table using C# datatable object in winform.

◀ DataTable object

I want to use a function like this. Is there a way to resolve a C# DataTable object to STDIN ?

The reason I don't want to do EF core is because it's difficult to find EF core tutorials for postgresql, so I don't want to try it.

There is a condition for doing this.

1. DataTable data built in C# cannot be converted to csv. (by the way, Is there a way to include csv in c# winform exe? Then I can use the csv method)