You have to remove the pocket and there is a connector underneath it for the audio jack. Some dealers (or their technicians) install them when they set up the bike, some don't so it gets lost.

 

Honda stopped supplying the aux cable. I'm not sure but i think it was the 2012-2017 when they added the usb plug on the audio system. You can order the cable though.
Like Dave430 said, the connector is under the left pocket hidden inside one of the rubber boots. Should be a white connector with three wires. There also should be a red connector with two wires for aux power.

 

Ok, sounds good, before i ordered connecter i was checking because in the 2015 owners manual under Auxiliary Function page 128 it states....
(Models equipped with Navigation System) The auxiliary input jack connector is located under the left fairing pocket.
My bike doesn't have navi and every place in manual that it says (Models equipped with Navigation System)
after i look on my bike it doesn't have it, so im questionable if the conector is under that left pocket. So i guess I'll have to open it and look

 

It's there - might be hard to find, but it's there.

BTW, the aftermarket cables are longer and less expensive.

 

I just looked at my manual. I think what they mean is that the nav model includes the aux "cord". All the models have the hookup in the left pocket.
I have a 2012 audio/comfort (no nav) and mine has it, but did not come with the cord. Using this connection for my Zumo GPS. I didn't have to buy the cord, took it from my 2004.

 

I opened the pocket and wires were right there. Cool thanks everyone, i put the Bluetooth device in and it works great, wishing i had gotten Bluetooth with mic, so may order that next