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The reason for this error is that the plugin is not available in the AppBuilder clients (Web, Desktop, etc.) or Companion App and cannot be loaded in the simulator, there is not a problem in your project. Because the plugin is added to the app package in the Build phase, it is not available in the project for testing in the simulator. Thus, even if the plugin is added to your project, you need to test the behavior on a real device and not in the simulator.