Will Allah do miracles for us in our time?

We know that before Allah did miracles for his slaves. Like Story of Zakariyah (Zechariah) PBUH. He asked Allah for child in very old age, But Allah made miracles and gave him a child. So is this even possible today. Like if a old man ask for child, will allah give him? So my question is if a person makes a dua that is only possible by Allah's miracle, Will there be a possibility that his dua will be accepted And allah will do miracle for him or The doors of miracles have shut down?