How do you find your host name for IIS to connect your wordpress for update

I have inherit a windows server (for wordpress website) with ISS installed (for wordpress) and configured. I am trying to update word press but it ask me for and FTP hostname , username, and password… I put the ip adress of our server as the host name with the correct username and password and I get ” ERROR: There was an error connecting to the server, Please verify the settings are correct.” the only thing I’m not sure on is the hostname being correct. May I please have some help to this problem?