Step 1: Microsoft App Developer

You can Register as a Microsoft App Developer for $14 as an individual developer. See the example below. This is the first step in developing Apps for your Xbox.

Step 2: Dev Mode Activation of your XBox

You need to download and Dev Mode Activation App on your XBox from the Microsoft store. See XBox One Developer Mode Activation and Putting Xbox into Dev Mode

Launch the Dev Mode Activation App and note down the Activation code which you need to enter in your Microsoft Developer Account.

Step 3: Create a new MonoGame Windows Universal Application (CoreApp)

MonoGame has to use DirectX for graphics support if you are deploying your game on Windows or XBox. You can copy all the code from your Cross-Platform Desktop Application (OpenGL), it should all work except for sound effects using MP3/OGG.
Your XBox and PC need to be wired in to the same network using ethernet cables to your router. In Visual studio you can run on the Local Machine or switch to the Remote Machine (XBox)

How to Deploy MonoGame to Xbox

If Dev Mode Activation fails

Activate dev mode through the hidden developer settings menu rather than the dev mode activation app. To access the hidden menu go to Settings > System > Console Info > Press LB RB LT RT > Developer Settings > Developer Mode

Sound Effects Only Work on XBox with Wav Files

Final Deployment 4K UHD Resolution (65 inch OLED Screen)