An active MTw sensor should by default be visible in the Device List of MT Manager when it is docked in the Awinda station.
First, please make sure that the LED of the MTw is blinking. If needed, you can power the Awinda station for a short amount of time to switch on the sensor.
When the docked MTw is not visible in the Device List, it is possible that you need to enable this in the preferences. Please go to Tools > Preferences > MT Manager > Miscellaneous. Enable the option "Show Docked MTw's in Device List (Rescan Required)" (see figure).