Settings Sync: Toggle Sync Automatically
sync.toggleAuto Sync after startup, shortly after a change, and at the interval set in Settings ▸ Sync.
How to run it
Open the command palette (M-x in the Emacs keymap) and search for Settings Sync: Toggle Sync Automatically, then press Enter. It has no default keybinding, but you can bind one in Settings → Keymaps.