Hi @ctzn99, I setup a new WPF project in Visual Studio 2019, then through the process manager setup the platform to be x64 only.
Then load manage nuget packages -> install Tobii.Interaction. and run the blank window.
Thereafter, within the project folder: packages\Tobii.Interaction.0.7.3\build\x64 you should find the 64bit DLL that you can port across.
Please try this out and let me know how you get on. Best Wishes.