In short, yes, electric scooters can go uphill. However, several factors determine whether your device can do this or not. The climbing angle is one of the most important ones. For scooters with less powerful motors, an angle higher than 18 degrees is too steep. For more powerful scooters, that angle is like a child's play.
The weight of the user is also very important. The exact same model can climb a hill with one person, and have a difficult time for another, due to the weight difference. The greater the weight, the harder it is for the electric scooter to climb the hill.
If your scooter comes equipped with a powerful battery pack, it will be able to provide more power. The battery and the motor have a direct impact on the performance of any scooter. The more powerful they are, the greater the performance of the unit.