RFID reader via RS232 in C# is there an example?

Question

RFID

Good evening!
It is necessary to write a C# program that interrogates the RFID tag reader and displays their identifier on the screen, in other words, create some primitive software for the rfid reader. It can be assumed that the reader communicates via RS232. I would be very grateful if you tell me in which direction to dig or have a similar example.
PS
I'm familiar with C#, but rather at a "basic" level.
I would appreciate comments.