OpenXR Feature Extension for Unity

So recently I noticed OpenXR added support for FOV and Display Refresh Rate so I started to invest some time into figuring out how to enable them and change values in runtime. So after a week of a full mental breakdown of not getting anything at all to even get called i started to question my ability of human being. 

I could need some help to activate / enable this in my project: 

 

I also noticed they needed to get a featureID of packages? 

I really don't get where people can find those addresses. Etc: "com.unity.openxr.feature.example.intercept"

So I came to this amazing forum to finally get some pro help.