Your camera doesn't have to "know" that the flash should fire when you're using a "dumb" (no TTL) flash; the hot shoe's centre-pin firing circuit is closed (turned on) when the shutter is open regardless of whether a flash is attached or not. All of the more complicated communications that happen for iTTL or manual CLS control happens through the other pins, which your manual flash doesn't have. The centre contact on the camera's shoe, though, is a much smaller and more fiddly target now than it was in the days before multi-contact TTL flashes, so you'll need to make sure that the flash trigger adapter (or wireless transmitter, should you decide to step up in the future) is properly seated in the hot shoe. From your set-up photograph, it looks like you haven't got the adapter far enough forward to properly engage the centre contact.
As for settings on the camera, all you really need to do is to make sure that you are in Manual mode (so that you have control over both your shutter speed for sync and ambient exposure and aperture for flash exposure and depth of field) and that your shutter speed is at or below your camera's X-sync speed (1/250 or slower).