Open it, go into the settings, hit preferences, go to the top where you see system.model bla bla bla, right arrow to the second tab, find a combo box where your options are one time code, on screen code, or never, set to never, now you go to control center on the iPhone and select screen mirroring. If it isn't there, you have to go add it to the control center under settings. Once you have selected that, your desktop's name shows up, double tap and the mirroring starts.