Plug the OSRAM Smart+ Plug into a power outlet.

In the Philips Hue app, open the Light Setup.

Add the OSRAM Smart+ Plug as a new light and change its name.

Add the Homebridge plugin homebridge-hue to your configuration and restart the Homebridge server.

In the server's terminal, enter sudo ph -H X.X.X.X -u ABC outlet -v, where X.X.X.X is the Philip Hue bridge's IP address and ABC is the password created while restarting the Homebridge server with homebridge-hue enabled for the first time.

Restart your Homebridge server.

In the Home app on your iPhone, change the device type of the OSRAM Smart+ Plug to outlet.