Build OpenCV DLL for MS Hololens2(Unity)

I am using Unity to develop programs for MS Hololens2. Here, I am going to use OpenCV (C++ DLL) for image processing.
In Unity, I changed the platform to Universal Windows Platform (UWP) and built it, and installed the Windows SDK and Hololens2 emulator. In order to develop a library using OpenCV, a DLL was created with a Universal Windows dedicated DLL project (C++). At this time, OpenCV proceeded using World.dll released from the official website.
However, if the emulator calls a function in the DLL, it throws an exception saying that it cannot be loaded.

There is no problem with how to create and build a DLL project for OpenCV. Because when I tested it without using OpenCV, it worked without any problems. Therefore, I thought I had to rebuild OpenCV World.dll using CMake, and even though I tried various things, it still didn’t work.
Of course, the Unity project also included OpenCV World.dll and built it. (I tried to exclude it, but it still didn’t work)

I searched for materials related to cross-compiling and tried to repeat it, but I couldn’t do it properly.
Are there any resources to reference? How can I do it?

OS: Windows10 (x64)
OpenCV: 4.5.0
Unity: 2019.4.22f1
Visual Studio: Visual Studio Community 2019

opencv dlls will load further dlls, as far as I’m aware. one of these would be a dll for ffmpeg support.

make sure all the stuff can be found (is in PATH). you can “try things”, or you can run your program from Dependency Walker and track down what’s really missing and what’s merely noise (those uppercase dashed names containing “RT” it’ll report aren’t really missing)

just a guess. I am unfamiliar with Unity.