We got a Lutron Maestro CL Light Switch. It’s two switches, one master and one slave.
It’s all fancy. Here’s the instructions.
Most important thing I learned after calling tech support: It doesn’t work well with my LED bulbs. So I put one 40 watt incandescent in the set and it works perfectly. When it’s not working, the on/off switch only works sporadically and can’t be programmed.