Use a bloom food on a regular basis so it can build up energy to bloom next year. I would recommend a water-soluble powder form at 1/2 strength on a weekly basis. Once it goes dormant keep it in a cool-ish place until September/October then plant it in the ground or start watering it again to grow it in the pot again. The flowers won't be as dense and compact as what it has now, but they'll still smell wonderful.
Happy Plant Parenting