Hey,

sorry that it took me so long to get to this. Great work!
What I noticed:

• This unfortunately doesn't work inside the flatpak. Here's how the os plugin solves this by using flatpak-spawn
• Unfortunately, the app id doesn't support dots, please replace them with underscores. The format should be com_example_app

You can test if your plugins installs and works correctly in the Flatpak by installing StreamController via Flatpak and then adding your repo as a custom plugin in the settings:

Thanks for your work and looking forward to having your plugin in the store!