Show those due date tasks to me

I am new to the kanboard.
I try to use the Kanboard to manage my projects.
I do not understand the notification function, please help me if someone know.

I create some projects, for example,
proA: taskA1, taskA2,…
proB: taskB1, taskB2,…
proC: taskC1, taskC2,…

I setup one task, for example proB:taskB2, let its due date=time1

my question is:
when I am working at other proA board not proB:taskB2, if Now the time is due data time1, how to configure to receive the notification to let me know proB:taskB2 is under due date situation. Then I can turn to deal with the taskB2.