Install

1. Add the release PGP keys:

   sudo mkdir -p /etc/apt/keyrings
   sudo curl -L -o /etc/apt/keyrings/syncthing-archive-keyring.gpg https://syncthing.net/release-key.gpg    
   echo "deb [signed-by=/etc/apt/keyrings/syncthing-archive-keyring.gpg] https://apt.syncthing.net/ syncthing stable" | sudo tee /etc/apt/sources.list.d/syncthing.list
   printf "Package: *\nPin: origin apt.syncthing.net\nPin-Priority: 990\n" | sudo tee /etc/apt/preferences.d/syncthing
   sudo apt update && sudo apt install -y syncthing
   

2. run syncthing from bash to continue setup

3. Once it is set up the way you want, enable it as a user service, as according to the documentation:

   Edit using:

   systemctl --user edit syncthing.service
   

   systemctl --user enable syncthing.service
   systemctl --user start syncthing.service  
   

   Check the status using:

   systemctl --user status syncthing.service
   

   stop and disable using:

   systemctl --user stop syncthing.service  
   systemctl --user disable syncthing.service  
   

4. add syncthing to your firewall rules

sudo ufw allow syncthing
sudo ufw allow syncthing-gui

1. Configure it to connect to your other computers

External Resources

https://docs.syncthing.net/users/faq.html#how-do-i-reset-the-gui-password