Referencing another project in .Net Core

Edit your MyProject.csproj file. And add a new ItemGroup or add your package into an existing ItemGroup. Here's example:

  <ItemGroup>
    <PackageReference Include="Polly" Version="7.2.0" />
    <ProjectReference Include="..\SomeOtherProject\SomeOtherProject.csproj" />
  </ItemGroup>

It looks like you've created everything as web sites, but I suspect that most of those projects should actually be class libraries (dlls), not sites. You might need to reset a few things!

You should be able to right-click on the Dependencies node to add a project reference:

or the project node:

then:

Alternatively: edit the csproj and add a <ProjectReference> node: