OK, I see. You first need to scry the person. From that you will see the person's location and then be able to open a gate.
Hi and welcome to theRPGsite!
Sorry for the delay in answering, too.
Evermaster already answered the question correctly, but I thought you might appreciate some additional information regarding choices. In LoO, there are obviously powers that equate to powers from Amber, but ALL of them (all the major ones, anyways) are set up to be a little slower and a little harder to use on the fly than their equivalents.
This was on purpose, because I had often found players in my Amber campaigns trying to use powers for combat purposes, in ways that were not strictly contrary to rules-as-written but that didn't seem to me to fit the intent. In any case, I decided to make the capabilities and limitations of the powers a little clearer, and to tone down the potential range of the powers by making it take more time and effort to use powers.
Powers can STILL be used in combat situations, but normally not 'off the fly'; they require that you be prepared for the conflict beforehand.