How to enable XR settings in player of project settings?

Getting Started
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1

I would like to use MRTK in Unity for deploy project to HoloLens 2
In order to achive this goal, I have install:

  1. Window 10 SDK
  2. visual studio 2022
  3. Unity 2019.4.40f1
    furthermore, I also have imported MRTK2.0 or 2.4 package
    Next, I also Install XR Plug-in Management and checked Initialize XR on Startup and Windows Mixed Reality. But, when I aimed to set the Lagacy XR, it was unenabled.
    Does any one know how to fix it?
    I really want to kow how deploy project to HoloLens 2！
    thanks!