CODE EXAMPLE FOR JAVASCRIPT

react native metro api level 30

// in ./android/build.gradle
ext {
  buildToolsVersion = "30.0.2" // <-- 
  minSdkVersion = 21
  compileSdkVersion = 30 // <--
  targetSdkVersion = 30 // <--
  ndkVersion = "20.1.5948944"
}