“parnassa is min hashamayim”
That may be so, but it does not continue to say that the parnassah will FALL from Shamayim. That phrase means that Hashem decides what we will earn during the year. It does not mean that we have no achrayus to put in our hishtadlus in order to get that parnassah. Der Aibishter vet helfen, doesn’t mean we have no responsibility in the matter.