Can't make apk file in processing 3.5.4?

Question

Java

Hello! When I click File>Export Signed Package
, I get the message that they say change the name of the application in the manifest, changed it to "com.example.cubesgame".
I try again, it knocks it out:

I did various manipulations, and read the documentation, nothing about icons is indicated there, here is my code:

void setup() {
  fullScreen();
  noStroke();
  fill(0);
}

void draw() {
  background(204);
  if (mousePressed) {
    if (mouseX < width/2) {
      rect(0, 0, width/2, height); // Left
    } else {
      rect(width/2, 0, width/2, height); // Right
    }
  }
}

I have not downloaded the emulator yet, is it required to make apk?
my manifest file:

manifesto

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
          package="com.example.cubesgame"
          android:versionCode="1"
          android:versionName="1.0">              
    <uses-sdk android:minSdkVersion="17" />    
    <application android:label=""
                 android:icon="@mipmap/icon1">
        <activity android:name=".MainActivity"
                  android:theme="@style/Theme.AppCompat.Light.NoActionBar.FullScreen">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity> 
    </application>
</manifest>

Answer 1

The emulator is optional, but desirable, because. on it you can check how your APK works.
As for the error: this does not seem to be an error, but a warning so that you do not try to upload APK with default icons, but create your own to be included in the APK.
And what's stopping you from installing a normal Android Studio, an emulator, and working like all white people?