This was just some simple test code for my first Kotlin code in rdzwx-plugin. Its now a mostly usable app, not not really well-tested. Use at your own risk :)
See https://github.com/dl9rdz/rdzwx-go/wiki for details how to use.
Install Java (I used openjdk 11, gradle and android on API level 30 do not support later openjdk version) and gradle (I used version 7.4.2) (I installed both on MacOS with brew)
Install Android Studio (currently tested with Chipmunk 2021.2.1)
In Preferences: Appearance&Behaviour > System Settings > Android SDK
SDK Platforms: select some relevant platform (I used API level 32)
SDK Tools: I selected Build-Tools, NDK, SDK command line, emulator, SKK platform tools (maybe not all necessary) Specifically, build tools 30.0.3 are needed!!!
export ANDROID_SDK_ROOT=/Users/me/Library/Android/sdk
Use path shown in Android Studio preferences as "Android SDK Location"!
Install node.js (after that you should be able to run "node" and "npm" on your command line) (On MacOS I did 'brew install nodejs')
Install Cordova (used version 9.0.0): sudo npm install -g cordova
clone the git repository (git clone https://github.com/dl9rdz/rdzwx-go.git)
cd rdzwx-go; cordova platform add android
cordova plugin add cordova-plugin-androidx-adapter
npm i jetifier
npx jetifier
cordova build to build debug apk
cordova build --release to build releaes apk
cordova run android to upload apk via usb to phone