At the time of this writing, an Alexa routine can only be triggered by a contact sensor, motion sensor, lock, Echo brand button, or flic brand button. It cannot be triggered by a “switch“ of any kind.
So What @bjpierron did was create a virtual device which had BOTH The switch and sensor capability. When you turned on the switch, the sensor would look like it was open, and so the sensor part could be used to trigger an Alexa routine. That’s what is meant by an “Alexa switch”— it’s just a switch which also has a sensor capability. That way Alexa will trigger Alexa routines from it.
The new virtual devices from @taustin have many different variations, but there are definitely some that have this same ability. That’s discussed at length in the author thread about that edge driver. But they’re usually described the other way around: as a sensor that has a switch capability rather than as a switch that has a sensor capability. But they end up working the same way. 
If you are not able to figure out how to trigger an Alexa routine from one of the virtual devices created by that Edge Driver, just ask in that author thread and someone should be able to help you. You might need a slightly different variation.
[ST Edge] vEdge Creator: a virtual device generator for end users