Trying to run on an Android device (Huawei Mate 20 Pro). I am running Unity on Ubuntu 18.10 (Unity build 2019.2.12f1) and I have installed the Android SDK & NDK tools using the Unity Hub but when I try to “Build and run” with Android as my target platform, I get “Unable to locate Android SDK”.

I have tried to manually install the SDK using apt and I have referenced that location in the External Tools window but no difference. What am I doing wrong?
Manual Install location:

