QuickOPC User's Guide and Reference
Installing Assemblies (.NET)
For COM and Excel applications, you need to deploy all files from Components\Opclabs.QuickOpc\net472 subdirectory (in the installation directory of the product). This includes all .DLL files, and an assemblies.config file which contains the necessary binding redirections.
Remember that in .NET, the deployment will contain not only the files of your application and QuickOPC files, but also the files from NuGet packages that QuickOPC depends on, and that you have to comply with their licensing requirements as well.
In .NET Framework, you need to deploy the contents of the output directory (e.g. bin/Release) of your build tool. This includes all assembly files needed, and also the .config file which contains the necessary binding redirections.
In .NET 6 or 7, the assemblies that become the part of the deployment are determined and included automatically by the tools that build the deployment. For more information, see Microsoft's article .NET application publishing overview.
QuickOPC applications in Python use the Python Packages of QuickOPC. The .NET assemblies (for both .NET Framework .NET 6+) and are contained within them as data files. No special treatment is necessary with regarding to deploying them; properly functioning Python tools should recognize them as such, and include with other parts of the package needed for the deployment.