I've had a look at my Seculite and can't see anything other than the spade terminals. I know some B&M rear lights have this bare wire connector but does the Seculite?
The “plus” certainly does. I can see the holes, but they appear blanked. My expectation is the the “blade” part pulls or hinges out to expose a clear hole, wire poked in, then blade pushed in a la Scotch connector, cutting the insulation through to the wire. I confess the instructions, such
as they are, are still in the shed, so it may be that the wire needs stripping first before poking in. I’m loathe to just press part “C” without a wire in place (to see it it’s already in the “open” position rather than needing to be opened) in case the action is irreversible.
The instructions are frankly utter pants in this case.