The mailbox is also equipped with an electronic lock like the rest of the builing.You can open your mailbox the same way you open your apartment.
Don't forget to lock after opening. You do not need to use your phone for locking.
Please note that you will share the mailbox with your floor. We chose not to provide individual mailboxes anymore since they are not used as often as before, and we don't want to needlessly burden the environment.
Just take out your own mail, leave what is not yours please.