This one's not hardy outside, so when its done, place in a cool room with good light (a north facing room is ideal), keep it watered and fed, and if you like, when the risk of frost is over (at least end of May) you can stand it outside in a shady spot, out of direct sun, but not dark, again keeping well watered and fed. Bring back in at the end of summer to a cool room, and hopefully, it will flower again. You can just leave it in a cool, bright room rather than placing outside if that suits better. Deadhead as soon as the flowers fade.

thank you bamboo.Do you mean just remove dead flowers, or pinch back, like rhoddedendroms, and outdoor azealeas

No, just remove faded flowers.