buzz for (one)
To use a device that makes a buzzing sound (such as a doorbell or intercom) to try to get one's attention. When you get to my apartment building, just buzz for me, and I'll let you in. Buzz for the receptionist and ask her what's taking so long.
buzz for someone
to sound a signal for someone. Please buzz for the bell captain. I buzzed for my secretary and waited for a reply.