When I go to Facebook Settings, it says under Android Build Facebook Settings: "You don't have the Android SDK setup! Go to Unity->Preferences... and set your Android SDK Location under External Tools"

But - in the External Tool section of Preferences it says: JDK installed with Unity is based on OpenJDK 1.8.0_152, and all checkboxes below are on. And I correctly have installed Android Build Support including Android SDK & NDK Tools, and OpenJDK. Does it need a different version? I remember that in previous Unity versions I had to install Android SDK, but in Unity 2019 I did that with the Unity Hub.

I have downloaded the latest Facebook SDK: 2.18.0