Question Missing target device option in unity 2021 ?

Hello,
I am following this exercise to learn building app for HoloLens:

https://docs.microsoft.com/en-us/le...ise-configure-unity-for-windows-mixed-reality

in the exercise, it used unity 2020.3.24f1. However, in unity version 2021.3.2f1 (even 2021.3.3f1) that I install and use, it doesn't have the 'target device' option, where I can select "HoloLens"
In the menu bar, select File > Build Settings....
In the Build Settings window, select Universal Windows Platform.
Target device option is NOT there.!

Am I missing something ? (BTW, I downloaded and installed unity 202.3.24f1, with this version, it does have the 'Target device option'. So, why unity version 2021.3.2f1 and 2021.3.3f1 don't have that options ? do they deal with HoloLens differently ? )
I am new to Unity and HoloLens, any helps with building app for HoloLens are greatly appreciated.
thank you.
Soho.

 

thank you for the answer. I was so caught up with that option. thinking it was the only option to deploy it over to HoloLens. as it turns out, that is not the case.