Hi @GRAHAM_MACRAE welcome to Zwift forums and Zwift in general.
The Virtual Run is a Garmin feature for runners only.
You don’t need a similar thing for cycling because your Garmin Speed and Cadence sensor will connect to the Zwift game app via Bluetooth. It’s a whole lot simpler to get started if you leave your Garmin watch out of your setup entirely.
Please follow these steps on our support hub to get started.
If you are running the game app on a Windows computer, you may want to use the separate Zwift Companion app on a smartphone to create a “Bluetooth bridge.” What’s that? More info about that here. A very important thing about using ZC in this way is to make sure that your Windows laptop and your smartphone are both connected to the same WiFi network.