How to rename app package in flutter project?

Question

I want to rename my app package.

I can't upload my app on play store because my app package is com.example.example. How can I change it easily?

For Android

Goto, app level build.gradle and specify your unique applicationID

    defaultConfig {
    applicationId "your-package-name"
    minSdkVersion 16
    targetSdkVersion 27
    versionCode flutterVersionCode.toInteger()
    versionName flutterVersionName
    testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    multiDexEnabled true
}

For IOS

Goto, Info.plist inside ios/Runner directory and change the bundler identifier

<key>CFBundleIdentifier</key>
<string>com.your.packagename</string>