How to install Nuget package using windows command line in C# project?

I have downloaded NuGet version - 5.1.0 and tried to install one of the package - log4net using cmd. it failed. below is error -

Microsoft Windows [Version 10.0.19042.1348] (c) Microsoft Corporation.All rights reserved.

D:\Personal\ConsoleApplication1\ClassLibrary1>"D:\Personal\ConsoleApplication1\nuget_1\nuget.exe"install-package log4net Unknown command: 'install-package'NuGet.CommandLine.CommandLineException: Unknown command:'install-package' atNuGet.CommandLine.CommandManager.GetCommand(String commandName) atNuGet.CommandLine.CommandLineParser.ParseCommandLine(IEnumerable`1commandLineArgs) at NuGet.CommandLine.Program.MainCore(StringworkingDirectory, String[] args)

D:\Personal\ConsoleApplication1\ClassLibrary1>

Here, ClassLibrary1 is C# project where I have to add log4net package. I don't want to use NuGet Package Manager Console option available in Visual Studio.

Did I write correct command?