To be an ATC on this server you need to use the very handy tool, Flight Strips. When you set up as ATC you need to open up an airport on flight strips and set your frequency, the ICAO code, the position (tower/approach) and how long you will stay. You will notice there is the option to select your ability level. Be honest. If you have set your rank as four stripes, expect a more in-detailed conversation and requests from the pilots. You should always ensure your ranking is the same on Flight Strips as it is on the website (You must apply to become aqn Air Traffic Controller).
Here is a short tutorial.
A very good feature of flight strips is the “map”. If you operate as ground, you can use the map to see all the taxiways and where on the taxiways the aircrafts are.
In flight strips, there is a chatbox where you can communicate with other controllers.
It’s very important that if you set up as an ATC position in an airport where there’s another ATC active, you need to talk to him first and ask if it’s ok, and what runways he’s using.
The main chat source for the ATC’s is via flightstrip so keep an eye on it.
When you are online as ATC in flight strips, you should keep your aircraft strips and edit them if needed if the pilot changes something. For exampel if the pilot wants to fly a higher crusing altitude, you need to change that on the strip.