How to use stage recorder extension?

I am learning stage recorder extension, following this only available tutorial about it:
https://docs.omniverse.nvidia.com/prod_extensions/prod_extensions/ext_animation_stage-recorder.html

In the above doc it is told that I can the access the Stage Recorder window by:

  1. clicking the “record” Icon in the timeline window

Well, I do have not such a icon in my timeline in Composer:

  1. by selecting Window/Animation/StageRecorder

Eh, I do not have that either:
image

My extension is ON and set on autoload.

So I do have that menu item, but I cannot follow the tutorial on usage of this tool if I cannot open that Stage Recorder window…
image

I installed Machinima to see if I could access this Stage Recorder window from there, but no its not even listed in the extensions.

Am I the only one having this exiting new tool missing?