Filesystem permissions

Hello, I recently created my first Flatpak, WhatsApp Desktop.

My app uses the official webpage, using the latest Electron. Attaching pictures or files opens the file chooser portal and everything goes well, but when it comes to downloading pictures or files from a conversation, the page opens the system file picker, thus nothing shows up as the app has no permissions to see the file system.

I can’t fix this since it’s an upstream problem, so what do I need to do? Give host permission?

You could manually use Portals. You use D-Bus to tell the host to open a file picker outside of the Sandbox. After the User chooses a File, the Flatpak get access to that file.