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PC download: https://syncthing.net/downloads/

To enable Syncthing GTK in Game Mode, you will need to create a new text file located at /home/deck/.config/systemd/user/

Create a text named ‘syncthing.service’ and the contents of the file will be:
[Unit]
Description=Syncthing
[Service]
Type=simple
ExecStart=flatpak run –command=syncthing me.kozec.syncthingtk
Restart=on-failure
RestartSec=1
SuccessExitStatus=3 4
[Install]
WantedBy=default.target

Then open Konsole and run the commands:
systemctl –user enable syncthing
systemctl –user start syncthing

If you wish to disable Syncthing starting on launch you can run the following commands:
systemctl –user stop syncthing
systemctl –user disable syncthing