In order to add the ability to switch the dimmer from another switch, we can add a couple of wires a to the TYWE3S chip inside the DS01 dimmer.

Wiring

I chose to use GPIO-12 and GND.

Wires were soldered onto GPIO-12 and GND and run through the back of the box.

Configuring

Configure GPIO-12 as Switch(9) in the module configuration of Tasmota.

From the console, add the following rule:

Rule1 on switch1#state do power toggle endon
Rule1 1

Now when you connect or disconnect the two wires (GPIO-12 andGND), the dimmer will toggle power.

References