Open FocusOS. The pairing code is on its first screen, at the bottom — there's a copy button next to it. Paste it here.
What this does: while a focus session is locked, FocusOS can see
which tabs are open, so one site can be your work while another isn't.
Without it your whole browser is a single item on the list.
It only ever talks to FocusOS on this computer (127.0.0.1), only with the
code above, and only while FocusOS is running. Nothing leaves the machine.