First thing...I've no experience with this exact hitch. I've owned a similar slide bar hitch, and have seen others being used.
The slide bar, when fully open, handle in proper position, likely pointing up, should close automatically when the pin glides back into the hitch.
IMHO, this hitch (entry level slide bar, often provided by selling dealer) is not a good choice for FW towing. In general, they are noisy, due to sloppy fit, and will get worse over time.
Will it work? Yes, but for just a little more, you can get a much better wrap around jaw style. I am familiar with B&W hitches, and their Patriot hitch would be a much better choice for you.
In any case, congrats on the new FW, you will enjoy the tow.
Jerry