In order to connect the mount with StarGo Plus/StarGo2 Pro driver with N.I.N.A. is required to choose the Avalon UD Telescope driver from the Telescope drop down menù list. This option will be available only after it will be selected with the ASCOM chooser.
Inside N.I.N.A. is not possible to launch the ASCOM chooser from the Telescope section menù so it is required to do this operation at least once by using external software app, as for example Carte du Ciel, Stellarium etc...