About a year ago, I had my parents' kitchen faucet professionally redone by a plumber when I spotted a leak and didn't think to check if the spray line worked or not before they left (I know, I know... now that I have more experience I realized that was a huge mistake). We were renting the house out to relatives at the time who also didn't report to me that it didn't work, so obviously it's been too long for me to claim that it's the plumber's fault and for them to fix it for free.

With that out of the way, I need some help fixing the spray line on some mostly brand-new fixtures. It is a separate line from the main faucet and is hooked up to a diverter. When I turn the faucet on, I can see water going through the spray line but it doesn't feel "pressurized", and when I push the button to spray, at most I see some droplets dripping out. Nothing happens at all if I push the button with the faucet off (although I don't know if that's just normal function). Photo of the fixtures attached. I would greatly appreciate any help... thank you!