If you want to control multiple Insteon lights and appliances with a single voice command or control Insteon devices alongside connected home devices from other manufacturers that are also supported by Amazon Echo, create groups in the Amazon Alexa app.
Add Insteon Hub to the Amazon Echo App
Launch the Alexa app and tap the drawer button in the upper left corner
Tap Smart Home
Tap Create Group
Give your group a name and select the devices that you would like to include. When ready, tap Save.