Can't install "Microsoft.EntityFrameworkCore.Tools.Dotnet" in ASP.NET Core

I have a Class Library named DataLayer and wanted to install some nuget packages to it.

I have successfully installed the packages below:

• Microsoft.EntityFrameworkCore (version 5.0.8)
• Microsoft.EntityFrameworkCore.SqlServer (version 5.0.8)

When I try to install the following package, however:

• Microsoft.EntityFrameworkCore.Tools.Dotnet (version 2.0.3)

I get this error :

Severity Code Description Project File Line Suppression StateError Package 'Microsoft.EntityFrameworkCore.Tools.DotNet 2.0.3' has a package type 'DotnetCliTool' that is not supported by project 'DataLayer'.

I've restarted Visual Studio several times and also deleted my Class Library one time, but the error keeps occurring. Can anyone help me?