You are most likely getting your .dll reference from your local computer. From the GAC maybe, probably. Or hard coded to a long full-file-name-path.
You should consider using nuget to pull down your dependencies.
https://www.nuget.org/packages/Microsoft.Azure.ServiceBus/3.4.0
This will allow your references to be in a relative path, and will work on your build-machine if/when you get one.
This below article will help you bridge the gap with Visual Studio and Nuget:
https://docs.microsoft.com/en-us/nuget/quickstart/install-and-use-a-package-in-visual-studio
Quickstart: Install and use a package in Visual Studio (Windows only)
07/23/2018 3 minutes to read
+1 NuGet packages contain reusable code that other developers make available to you for use in your projects. See What is NuGet? for
background. Packages are installed into a Visual Studio project using
the NuGet Package Manager or the Package Manager Console. This article
demonstrates the process using the popular Newtonsoft.Json package and
a Windows Presentation Foundation (WPF) project. The same process
applies to any other .NET or .NET Core project.