Unable to add Microsoft.AspNetCore package to the class library project

I have an ASP.NET Core 7 project which has a reference from a shared class library project. In my shared class library, I have a method which access a webApplication object as argument.

The problem is that this class is part of the Microsoft.AspNetCore package and I could not find this package in nuget package manager to add my shared class library project.

Can anybody help me how to solve this problem?

Thanks in advance

Solution

I searched and found this section which metioned

To reference ASP.NET Core, add the following element to your project file:

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <TargetFramework>netcoreapp3.1</TargetFramework>
  </PropertyGroup>

  <ItemGroup>
    <FrameworkReference Include="Microsoft.AspNetCore.App" />
  </ItemGroup>

</Project>

And I create a Class Library and test it.