The is not an official product from Unity Technologies. Instead, it is a compatibility module developed by the Joiplay team (and open-source contributors) that enables Joiplay to:
If you’ve tried running Unity-based PC games on JoiPlay, you may have noticed they don’t always "just work" like older RPG Maker or Ren’Py titles. While JoiPlay is a powerful launcher for many engines, Unity support requires a specific setup to bridge the gap between PC executables and Android hardware. unity+plugin+for+joiplay+work
If it still fails – the game likely uses features beyond the plugin’s capabilities. Check the or Patreon posts for updated plugin versions. The is not an official product from Unity Technologies
This occurs if JoiPlay cannot detect the installed plugin APK. unity+plugin+for+joiplay+work