streamcontroller reports filesystem as readonly in flatpak directory

I receive the following error when trying to download any assets in streamcontroller, how might I make this not read-only for the flatpak?

OSError: [Errno 30] Read-only file system: '/home/username/.var/app/com.core447.StreamController/data/icons/com_axolotlmaid_FontAwesomeIcons'

OSError: [Errno 30] Read-only file system: '/home/username/.var/app/com.core447.StreamController/data/icons/com_axolotlmaid_FontAwesomeIcons'