I'm trying to install a Kasa HS200P3 smart light switch in my home hallway which currently has three manual switches to control the lights. One switch is located downstairs and and the other two are located upstairs at each end of the hall. I hooked up the mew smart switch connecting the green to ground and the white common wires. On my old switch there are two black wires connected on one side and a red wire on the other. So I hooked up the red wire to one black wire on the smart switch and I combined the two black wires from the house with the other black wire from my smart switch. It doesn't work. The switch does not turn the lights on or off manually. I have not tried to hook up to Wi-Fi because I can't get the switch to work yet. Should I connect the red wire with one of the black wires on the smart switch and then connect the two black house wires together with the remaining black wire on the smart switch? Or do I need a different smart switch? I also have two switches in the kitchen that I expect the same issues with. Thanks for any advice available.
Smart switch wiring question for multiple switches