Do I definitely need a programmable humidifier to control VPD in a 2 by 2 grow tent?

So I want to purchase a controller for my grow tent that can automate the VPD. I can buy the controller, inline and circulation fans in my locality but I can't find the humidifier that's compatible with the controller and I'm not sure when they'll be back in stock.

Would it be possible to buy everything just not the humidifier or would that not work?