Program used to log into state-owned digital mailbox fails on flatpak Firefox

Good day,

To log into the Swedish state-owned digital mailbox “Min myndighetspost” with your ID-card and a card reader, you need to use a program called SConnect Gemalto* that is installed as a plug-in in your browser as well as through the command line. It seems like it fails to make a connection between the plug-in in Firefox and the program installed through the command line possibly because of Flatpaks sandboxing. Anyone got a clue on how to solve the? It seems to make a connection with the RPM version of Firefox (on Fedora Silverblue), but I haven’t had any success tinkering with permissions on Flatseal.

*“SConnect provides a software layer that makes device drivers for tokens and card readers accessible in the browser.”
Official website with download instructions: Gemalto SConnect Install

Thanks in advance!

Edit: some corrections

In order to use a card reader, you normally need the pcscd service running and all or some of these packages installed: opensc ccid pcsc-lite pcsc-tools. Did you overlay these packages in your Silverblue installation?