xcode unable to open xcodeproj because pbxproj file is missing

I am trying to create my first iOS app. I am running Unity 2017.4.14f1 with Vuforia 7.0.57 on Windows. I am also using PolyToolkit version1.1. The build in Unity goes fine. When I try to open the project in Xcode I get a message that says “xcode unable to open xcodeproj because pbxproj file is missing.” The pbxproj file is generated during the build process and is visible in Windows Explorer on the PC and One Drive. However, on my MacBook Pro, the xcodeproj looks like a file rather than a folder. When I use the “show contents” option it cannot “see” the pbxproj file but sees a different file and folder. Am I somehow missing the insider MacBook Pro secret handshake? Does anyone know the fix for this? Can someone point me to a super detailed tutorial for building on windows and compiling on Mac with Xcode? I am also trying to build the same app on HoloLens, so that’s why I’d like to start on Windows....