Google Play Billing compatible with Godot 4.x?

Do you mean the docs at https://docs.godotengine.org/en/stable/tutorials/platform/android/android_in_app_purchases.html ?

Because this is the latest stable docs, I would assume that the module is compatible with 4.X, although that assumption could be incorrect. Best way to find out would be to try it out. If it doesn't work, then someone should open issues on the module repo as well as the documentation repo so things can be fixed.

I have made efforts and am not able to make it work with support in the documentation. Build failure continues

Look:
https://github.com/godotengine/godot/issues/81668

Try the last version godot 4.2.5 but

C:\Users\celso\OneDrive\Documentos\Godot\Encaixes\android\build>gradlew build
WARNING:We recommend using a newer Android Gradle plugin to use compileSdk = 33

This Android Gradle plugin (7.2.1) was tested up to compileSdk = 32

This warning can be suppressed by adding
android.suppressUnsupportedCompileSdk=33
to this project's gradle.properties

The build will continue, but you are strongly encouraged to update your project to
use a newer Android Gradle Plugin that has been tested with compileSdk = 33

Task :processDebugMainManifest
C:\Users\celso\OneDrive\Documentos\Godot\Encaixes\android\build\src\debug\AndroidManifest.xml:16:5-132 Warning:
uses-feature#android.hardware.vulkan.level was tagged at AndroidManifest.xml:16 to replace another declaration but no other declaration present
C:\Users\celso\OneDrive\Documentos\Godot\Encaixes\android\build\src\debug\AndroidManifest.xml:17:5-140 Warning:
uses-feature#android.hardware.vulkan.version was tagged at AndroidManifest.xml:17 to replace another declaration but no other declaration present

Task :stripDebugDebugSymbols
Unable to strip the following libraries, packaging them as they are: libc++_shared.so, libgodot_android.so.

Task :compileDevJavaWithJavac FAILED
C:\Users\celso\OneDrive\Documentos\Godot\Encaixes\android\build\src\com\godot\game\GodotApp.java:33: error: package org.godotengine.godot does not exist
import org.godotengine.godot.GodotActivity;
^
C:\Users\celso\OneDrive\Documentos\Godot\Encaixes\android\build\src\com\godot\game\GodotApp.java:41: error: cannot find symbol
public class GodotApp extends GodotActivity {
^
symbol: class GodotActivity
C:\Users\celso\OneDrive\Documentos\Godot\Encaixes\android\build\src\com\godot\game\GodotApp.java:42: error: method does not override or implement a method from a supertype
@Override
^
C:\Users\celso\OneDrive\Documentos\Godot\Encaixes\android\build\src\com\godot\game\GodotApp.java:44: error: cannot find symbol
setTheme(R.style.GodotAppMainTheme);
^
symbol: method setTheme(int)
location: class GodotApp
C:\Users\celso\OneDrive\Documentos\Godot\Encaixes\android\build\src\com\godot\game\GodotApp.java:45: error: cannot find symbol
super.onCreate(savedInstanceState);
^
symbol: variable super
location: class GodotApp
5 errors

FAILURE: Build failed with an exception.

• What went wrong:
  Execution failed for task ':compileDevJavaWithJavac'.

Compilation failed; see the compiler error output for details.

• 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 18s
49 actionable tasks: 49 executed

Is the plugin causing the issue? Are you able to export to android without the plugin?

Yes, I can export without the Android plugin google. But I need the plugin feature of integration with the google play store

According to the build log, I understood that the problem is in this import of the GodotActivity class, which it cannot find

import org.godotengine.godot.GodotActivity