Can I add the essential oil of Muji to the humidifier?

Not so good. Putting essential oil directly into the humidifier will cause damage to the humidifier itself. At the same time, when the essential oil is directly added to the humidifier, it will be mixed with water vapor to form a substance similar to a slight mist, which will not dissipate after staying in the humidifier for a long time, leading to indoor air pollution.