Add external project in nuget .nuspec file

I have an external .NET Core library that I want to include as a reference in a NuGet package I'm creating using a .nuspec file. Below is the folder structure I'm using. What else do I need to add to make sure that when someone installs this package, the .NET Core library is also automatically added as a reference?

<?xml version="1.0" encoding="utf-8"?>
<package>
  <metadata>
    <id>YourProject.Id</id>
    <version>1.0.0</version>
    <title>Your Project Title</title>
    <authors>Your Name</authors>
    <owners>Your Organization</owners>
    <requireLicenseAcceptance>false</requireLicenseAcceptance>
    <license type="expression">MIT</license>
    <projectUrl>https://yourprojectsite.com</projectUrl>
    <!-- <icon>icon.png</icon> -->
    <description>A brief description of your project.</description>
    <dependencies>
      <group targetFramework=".NETFramework4.8">
        <!-- Dependencies here -->
        
      </group>
    </dependencies>
  </metadata>
</package>

My goal is that when someone installs the package, the external library is automatically added as a reference

Answer

If you have any external project that you've referenced, you can add it as a file, just like I added the Alleva.B2C.dll file.

<?xml version="1.0" encoding="utf-8"?>
<package >
  <metadata>
    <id>Alleva.B2C.Legacy</id>
    <version>1.1.3</version>
    <title>Alleva.B2C.Legacy</title>
    <authors>John</authors>
    <owners>Hello Alleva</owners>
    <requireLicenseAcceptance>false</requireLicenseAcceptance>
    <license type="expression">MIT</license>
    <projectUrl></projectUrl>
    <!-- <icon>icon.png</icon> -->
    <description>Project decription</description>
    <dependencies>
      <group targetFramework=".NETFramework4.8">
        
      </group>
    </dependencies>
    <releaseNotes></releaseNotes>
    <copyright>Copyright 2024</copyright>
  </metadata>
  <files>
    <file src="..\Alleva.B2C\bin\Release\netstandard2.0\Alleva.B2C.dll" target="lib\net48" />
    <file src="bin\Release\Alleva.B2C.Legacy.dll" target="lib\net48" />
  </files>
</package>