how to make game object (fire hose) emit particle system (water) on mouse down

Hello, i am new to unity and currently working on a fire fighting simulation game. I have my game object (fire hose) and particle system (water) which is already being emitted but i want the game object to emit the particle system on mouse down. Any help?

Set your initial particle system emission rate to 0.

On mouse down, set it to the rate you want for flowing water.

On mouse up set it back to zero.