The kidneys (alone) don’t. They contribute to the cointrol mechanism regulating the blood pressures, pulse-rate, and the degree oif vasodilatation. But so do aqll other organs

All the organs of the body contribute signals according to their “need” (i.e., ‘Demand”) and also their ’satisfaction’ (i.e., “supply”). Clearly, the demand and supply is not the same for all organs, and so the brain has to make a compromise. It keeps Arterial Mean Pressure (Central aortic mean, that is) between strict limits.. Then all organs are supplied adequately.
The kidneys are just one of the inputs to this process. They don’t “CONTROL” blood pressure, -any more than (say) the digestive system, or the liver does. All contribute, but none -even the kidneys, has exclusive regulatory control, except possibly the brain, which is tasked with the job of choosing the optimum pressure, giving due weight to the importance of each organ.

angiotension feedback loop. You need to look it up, it can be a lengthy explanation. search renal hypertension, renal hypotension.