I wanted to use OpenCV on Android Studio, so I imported it while referring to the article.
I was able to import the module, but after that I got an error. I would like to know how to deal with it

upperappThere is a cross in the place, and if you look at Debug Configurations,
Warming: Default Activity not found
Will come out

AndroidManifest.xml

<? xml version = "1.0" encoding = "utf-8"?>
<manifest xmlns: android = "http://schemas.android.com/apk/res/android"
    package = "com.websarva.wings.android.opencv_sample">
    
        
          <intent-filter>
                
              <category android: name = "android.intent.category.LAUNCHER" />
          </intent-filter>
      </activity>
  </application>
</manifest>

build.gradle

apply plugin:'com.android.application'
apply plugin:'kotlin-android'
apply plugin:'kotlin-android-extensions'
android {
    compileSdkVersion 29
    buildToolsVersion "29.0.3"
    defaultConfig {
        applicationId "com.websarva.wings.android.opencv_sample"
        minSdkVersion 15
        targetSdkVersion 29
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile ('proguard-android-optimize.txt'),'proguard-rules.pro'
        }
    }
}
dependencies {
    implementation fileTree (dir: "libs", include: ["*. Jar"])
    implementation "org.jetbrains.kotlin: kotlin-stdlib: $kotlin_version"
    implementation'androidx.core: core-ktx: 1.3.1'
    implementation'androidx.appcompat: appcompat: 1.2.0'
    implementation'androidx.constraintlayout: constraintlayout: 2.0.1'
    implementation project (path:': opencv')
    testImplementation'junit: junit: 4.12'
    androidTestImplementation'androidx.test.ext: junit: 1.1.2'
    androidTestImplementation'androidx.test.espresso: espresso-core: 3.3.0'
}

https://qiita.com/tifa2chan/items/a2ec4f5d90eeb9cf1802

Android studio 4.0.1
Windows 10