Uploading Flutter App to Google Play - Please upgrade to Billing Library version 3 or newer to publish this app. Learn More about Billing Library 3

When uploading a flutter App to Google Play, I get the following error:

We've detected this app uses an unsupported version of Play billing. Please upgrade to Billing Library version 3 or newer to publish this app. Learn More about Billing Library 3.

I have updated the app/build.gradle dependencies with this:

dependencies {
    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
    def billing_version = "4.0.0"
    implementation "com.android.billingclient:billing-ktx:$billing_version"
  
}

I am using purchases_flutter plugin:

purchases_flutter: ^3.4.5

I have also run flutter clean multiple times.

Here is my flutter doctor output:

[✓] Flutter (Channel stable, 2.2.3, on macOS 11.2.3 20D91 darwin-x64, locale en-US)
• Flutter version 2.2.3 at /Users/jabari.garrett/Development/Tools/flutter
• Framework revision f4abaa0735 (3 months ago), 2021-07-01 12:46:11 -0700
• Engine revision 241c87ad80
• Dart version 2.13.4

[✓] Android toolchain - develop for Android devices (Android SDK version 30.0.2)
• Android SDK at /Users/jabari.garrett/Library/Android/sdk
• Platform android-31, build-tools 30.0.2
• Java binary at: /Applications/Android Studio.app/Contents/jre/jdk/Contents/Home/bin/java
• Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b3-6222593)
• All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS
• Xcode at /Applications/Xcode.app/Contents/Developer
• Xcode 12.5, Build version 12E262
• CocoaPods version 1.11.2

[✓] Chrome - develop for the web
• Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Android Studio (version 4.1)
• Android Studio at /Applications/Android Studio.app/Contents
• Flutter plugin can be installed from:
   https://plugins.jetbrains.com/plugin/9212-flutter
• Dart plugin can be installed from:
   https://plugins.jetbrains.com/plugin/6351-dart
• Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b3-6222593)

[✓] VS Code (version 1.60.2)
• VS Code at /Applications/Visual Studio Code.app/Contents
• Flutter extension version 3.26.0

[✓] Connected device (2 available)
• Android SDK built for x86 (mobile) • emulator-5554 • android-x86    • Android 11 (API 30) (emulator)
• Chrome (web)                       • chrome        • web-javascript • Google Chrome 93.0.4577.82

I can't create any Subscription because of this.

Any help is appreciated!