Can I use this smart dimmer switch with these wires?
You do not need a three way dimmer. The dimmer you have will work fine. Your existing switch is a single toggle switch. It's confusing because you have a black wire connected to a screw terminal and a black wire shoved into a backstab,(which is the same connection as the screw terminal). With the breaker &quot;off&quot; take the two black wires from your existing switch and connect them to the line wire from your new dimmer. Connect the red wire from your existing switch to the load wire from your dimmer. Connect the white wire from your dimmer to the neutral group in the box and connect the ground wires.