There is nothing aftermarket that will work right now on the "intended" harness for the 23's (the F45 connector in the luggage bay). This is because the 23's will require a converter that interprets CANBUS signals to decode the left and right turn signals and stop lights.
That being said - Tekonsha has indicated that there will be a 4-pin harness available for the 23's that does not use the "intended" tow wiring connector (F45). The part number for this is "118881". I'll link it below. Instead, this Tekonsha adapter will tap into both the left and right taillights, requiring you to remove more of the interior paneling during installation, and have less functionality than the KIA/Hyundai version. The Tekonsha will not have access to the reverse light (nor to the trailer brake power), as the reverse light signals don't route to the rear taillights. The reverse light signals on the 23's only go to the rear bumper (and to the rear camera in the upper part of the tailgate). So - that Tekonsha 118881 will only support a 4-pin and not a 5- or 7-pin.
The Hyundai official adapter should allow for a fully-wired 7-pin harness, from which you could convert down to a 4-pin easily.
Tekonsha | Brake Controllers
www.tekonsha.com