The Xiaomi Smart Humidifier 2 does not have a built-in sensor to measure the ambient humidity, so in the Mi Home/Xiaomi Home app you will only see the status of the device (power on, fog level, amount of water, timer, etc.), but not the percentage of humidity in the room. To view the humidity, you need to pair it with an external Xiaomi sensor (e.g. Mi Temperature and Humidity Monitor 2) that integrates into the same app.