Press keypad to access extension after play IVR

I got doubt about when people try to call to my asterisk server I would like the IVR play automatically. Then it would said please key in the extension number that you would like to connect. Then the person will key in the extension number.

But how to make this work when the person key in the extension number and it will recognise and connect to the exact extension.

Please advice and sorry if there is a post before on this topic and I haven’t search on it.

Thank you