Kestrel is not loading interop DLLL

Question

I have an F# Giraffe application using Kestrel. I am referencing an external DLL via a COM typelib, which generates a DLL named Interop.PCDCLientLib. I added a build event to copy that DLL into the $(OutDir), and I can see it in the proper directory "bin\Debug\net6.0-windows10.0.17763.0". The DLL is properly loaded in unit tests. However, when I run the application, I get an error: System.IO.FileNotFoundException: 'Could not load file or assembly 'Interop.PCDCLIENTLib, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null'. The system cannot find the file specified.'

I am trying to find if there is a another runtime directory to copy the DLL into so that it can be loaded. Where else should it go?