Virtual Dimmer Switch to control multiple lights through Alexa?

[TapioX]

@TOMillr

However, I fail to understand how to add actually devices to this virtual switch.

You can use Rules API rules to control actual devices.

Here are examples:

@TapioX

Using these Rules API rules Virtual Dimmer operates as master Light and
every time Master Light is operated rules copies the master light state to slave Light(s).