How to determine when fuel tank is low as it does not have specific marking analogue meter in Activa 6G?

On the Honda Activa 6G, you generally judge low fuel by the gauge needle moving into the red/last section of the analogue fuel meter rather than by a distance-to-empty display. If the needle is hovering near that lower end, refuel soon instead of stretching it, because analogue scooter gauges are no