Regardless of brand, the driver's weight greatly affects the scooter's ability to climb slopes. You can get over the steepest slopes by helping your scooter with a few kicks.
The Augment scooters, as well as their almost comparable 600-800 € competing scooters, manage 10-15%, i.e. 7-8 degree slopes with 80kg drivers.
Note that it is normal for the scooter's speed to decrease during the ascent. You can facilitate the ascent by accelerating before the hill.