I've editted Flutter source code like author's documentation but always having this error when building APK file:

```
FAILURE: Build failed with an exception.

* Where:
Build file 'F:\MyProject\android\app\build.gradle' line: 34

* What went wrong:
A problem occurred evaluating project ':app'.
> No signature of method: build_7lhgwn6g10f1dc3sk72t2tmig.android() is applicable for argument types: (build_7lhgwn6g10f1dc3sk72t2tmig$_run_closure2) values: [build_7lhgwn6g10f1dc3sk72t2tmig$_run_closure2@9578636]

* Try:
> Run with --stacktrace option to get the stack trace.
> Run with --info or --debug option to get more log output.
> Run with --scan to get full insights.

* Get more help at https://help.gradle.org

BUILD FAILED in 1s
Running Gradle task 'assembleRelease'... 2.787ms
Gradle task assembleRelease failed with exit code 1
Process finished with exit code 1

```

Line 34 in \android\app\build.gradle' is started with **android**.

This is app\build.gradle file:

```
def localProperties = new Properties()
def localPropertiesFile = rootProject.file('local.properties')
if (localPropertiesFile.exists()) {
localPropertiesFile.withReader('UTF-8') { reader ->
localProperties.load(reader)
}
}

def flutterRoot = localProperties.getProperty('flutter.sdk')
if (flutterRoot == null) {
throw new GradleException("Flutter SDK not found. Define location with flutter.sdk in the local.properties file.")
}

def flutterVersionCode = localProperties.getProperty('flutter.versionCode')
if (flutterVersionCode == null) {
flutterVersionCode = '1'
}

def flutterVersionName = localProperties.getProperty('flutter.versionName')
if (flutterVersionName == null) {
flutterVersionName = '1.0'
}

def keystoreProperties = new Properties()
def keystorePropertiesFile = rootProject.file('key.properties')
if (keystorePropertiesFile.exists()) {
keystoreProperties.load(new FileInputStream(keystorePropertiesFile))
}

apply plugin: 'com.android.application'
apply from: "$flutterRoot/packages/flutter_tools/gradle/flutter.gradle"
apply plugin: 'kotlin-android'

android {

compileSdkVersion 33

lintOptions {
disable 'InvalidPackage'
}

defaultConfig {
// TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
applicationId "my-package-name"
minSdkVersion 21
targetSdkVersion 33
versionCode flutterVersionCode.toInteger()
versionName flutterVersionName
multiDexEnabled true
testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
}

signingConfigs {
release {
keyAlias keystoreProperties['keyAlias']
keyPassword keystoreProperties['keyPassword']
storeFile file(keystoreProperties['storeFile'])
storePassword keystoreProperties['storePassword']
}
}

buildTypes {
release {

signingConfig signingConfigs.release

minifyEnabled true
useProguard true

proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
}

flutter {
source '../..'
}

dependencies {
testImplementation 'junit:junit:4.12'
androidTestImplementation 'com.android.support.test:runner:1.0.2'
androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
implementation 'com.google.firebase:firebase-core:17.3.0'
implementation 'com.google.firebase:firebase-messaging:20.2.4'
implementation 'com.android.support:multidex:1.0.3'
implementation platform('com.google.firebase:firebase-bom:30.2.0')
implementation('androidx.work:work-runtime') {
version {
strictly '2.6.0'
}
}
}

apply plugin: 'com.google.gms.google-services'

```

**Flutter doctor** => No issues found!

**Flutter --version**

Flutter 3.1.0-9.0.pre • channel dev • <https://github.com/flutter/flutter.git>
Framework • revision f28e570c8c (3 weeks ago) • 2022-06-14 13:39:33 -0500
Engine • revision 74ee6b5afd
Tools • Dart 2.18.0 (build 2.18.0-165.1.beta) • DevTools 2.14.0

**gradle --version**

---

Gradle 7.4.2
------------

Build time: 2022-03-31 15:25:29 UTC
Revision: 540473b8118064efcc264694cbcaa4b677f61041

Kotlin: 1.5.31
Groovy: 3.0.9
Ant: Apache Ant(TM) version 1.10.11 compiled on July 10 2021
JVM: 18.0.1.1 (Oracle Corporation 18.0.1.1+2-6)
OS: Windows 10 10.0 amd64

Can you help me? Thank you very much!