Cannot add System.Configuration.ConfigurationManager to .NET core application

Question

I need this package to access settings in the Web.config:

Restoring packages for D:\ ... path ... \dozor-backend.csproj...
Package System.Configuration.ConfigurationManager 4.4.0 is not compatible with netcoreapp1.1 (.NETCoreApp,Version=v1.1). Package System.Configuration.ConfigurationManager 4.4.0 supports:
  - net461 (.NETFramework,Version=v4.6.1)
  - netstandard2.0 (.NETStandard,Version=v2.0)
Package restore failed. Rolling back package changes for 'dozor-backend'.
Time Elapsed: 00:00:01.0720066
========== Finished ==========

I've seen other people use this package in net core app, so what's the issue? How can I use it in .NET Core app?

Solution

As error said, you can use System.Configuration.ConfigurationManager only starting from .NETCoreApp 2.0. For the previous version, you only have new ASP.NET Core configuration mechanism provided by Configuration API.

Regarding a provided link: reread it carefully, it doesn't say that ConfigurationManager` is available and works with the previous version of .NET Core.