Gradle build无法生成.apk文件

MyApp/
├── app/
│   ├── build.gradle
│   └── src/
│       └── main/
│           ├── java/
│           │   └── com/example/myapp/
│           │       └── MainActivity.java
│           └── res/
│               └── layout/
│                   └── activity_main.xml
├── build.gradle
└── settings.gradle

// Top-level build file where you can add configuration options common to all sub-projects/modules.
buildscript {
    repositories {
        google()
        mavenCentral()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:7.0.0'
    }
}

allprojects {
    repositories {
        google()
        mavenCentral()
    }
}

plugins {
    id 'com.android.application'
}

android {
    compileSdkVersion 30
    defaultConfig {
        applicationId "com.example.myapp"
        minSdkVersion 21
        targetSdkVersion 30
        versionCode 1
        versionName "1.0"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'androidx.appcompat:appcompat:1.2.0'
    implementation 'androidx.constraintlayout:constraintlayout:2.0.4'
}