XR integration steps for Oculus/Unity 2019

My XR integration toolkit for Oculus/Unity 2019 has stalled out. I ran into a wall in the Build platform for Android stage. Any advice much appreciated in how to get past this roadblock.

Instructions from Unity:

Install Android Tools Manually

If you’re using Unity 2018.x or prior, you need to install Android tools manually through Android Studio.

1. Download and install Android Studio Skip this step if you have it installed.
2. Open Android Studio, from the menu, go to Tools > SDK Manager.
3. Go to SDK Tools tab.

4.    Select Android SDK Tools from the list and click OK.

ISSUE, there is no SDK manager in the Android Studio Tools dropdown menu in the latest version that I just downloaded

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Steps I took prior: 

Packaging manager: Added XR Manager, XR interaction toolkit, Oculus XR

File>Build Settings

 -Added scenes

-Tried to change the Platform to Android. 

ISSUE 

 I got a “No Android Module loaded” error

Then clicked Open Download Page and got the error ““UnitySetup-Android-Support-for-Editor-2019.4.13f1 (1).pkg” can’t be opened because Apple cannot check it for malicious software. This software needs to be updated. Contact the developer for more information.

 Tried downloading Android plugins needed at

developer.android.com/studio

I opened the Mac pkg and installed it in my applications folder as directed.