You need to connect the shaft of the BLDC motor (electric to mechanic) to a component converting mechanic to pneumatic (gas) energy.
See the link below to the fan element (Simscape Fluids) https://se.mathworks.com/help/physmod/hydro/ref/fang.html
There is also a component in Simscape. https://se.mathworks.com/help/physmod/simscape/ref/rotationalmechanicalconverterg.html
Hope this helped Regards / Juan