@Khadija1 The two brass colored screws are the travellers, the black screw is the live/line

@Abdi7 don't forget to wrap that section of bare black wire with electric tape.

@Abdi7 If you can post pictures of the original switch wiring. Both sides and the back of the switch. And one of the wiring in the box.

@TaraV Treat switch 2 the same as switch 1. That will leave the jumper between both switches, so that a change in the future will not effect both switches.

@TaraV Treat the two black wires at the top of your picture as one wire. Put them and one black from the HS200 under a wirenut. Put the bottom black with the other black of the HS200 under a wirenut....

@Henrik... Log into the app on the other Iphone the same way you logged into the first one.