That's just the plug receptacle. You'll also need a few feet of 7-wire RV harness to wire into the connection under the truck and the plug you bought.
On my current rig I made a 4-foot long 7-wire extension cord and run it from the 7-pin receptacle on the bumper up into the bed only when towing a 5er or gooseneck trailer.
Grumpy ole man with over 50 years towing experience. Now my heaviest trailer is a 7,000-pound enclosed cargo trailer, RV is a 5,600 pound Skyline Nomad Joey 196S, and my tow vehicle is a 2012 F-150 EcoBoost SuperCrew.