Adding Android and ios Modules on 3.4.1 for 2021.3.1f1

Hello, I am new to Unity following the AR development pathway:

https://learn.unity.com/tutorial/co…344bfe21d8&missionId=63f63a3bedbc2a663dc6ffde

I have downloaded the asset file but I am stuck at stage 5. Install Unity with Android or iOS build modules, this is what I see:

The add modules option does not appear under the gear icon for me to add Android modules, I have checked the pathway to the files and it is the correct place.

Any ideas, please?

You have to install 'em via the Hub I think, with each individual version of Unity you have on the system.