How to change API level in Android Studio?

Previously it was done from the fileAndroidManifest.xml

<uses-sdk android:minSdkVersion="19"
          android:targetSdkVersion="28"
          android:maxSdkVersion="28" />

now it should preferably be done inside the /app/build.gradle file , even these values ​​override those defined in AndroidManifest.xml:

android {

    ...
    defaultConfig {
        minSdkVersion 19
        targetSdkVersion 28
    }
    ...
}

If you want to do it from "Project Structure" there you can only modify the values ​​of compileSdkVersionand buildToolsVersiondefined in your project.

android {
    compileSdkVersion 28
    buildToolsVersion "28.0.3"

    defaultConfig {
        minSdkVersion 19
        targetSdkVersion 28
    }

}

from the menu, go to File> Project Structure, select your app and selectModules

Choose the API level you need

API level

Not finding an answer, I was checking and it turns out that if we should go to project structure/modules/app, and where it says compile sdkversion, change the level, and according to the Android Studio documentation https://developer.android.com/distribute/best-practices/develop/target-sdk .html must be chosen Android 9.0 (API level 28)

and set this in the manifest:

<uses-sdk android:minSdkVersion="23"
  android:targetSdkVersion="28"
  android:maxSdkVersion="28" />