The FRTOL is the radio licence you need to legally be able to use the radio in an aircraft. Everyone who flies and uses a radio needs this licence (commonly referred to as an RT licence).
To gain a FTROL, you have to pass an oral exam. You effectively sit in a class room and practising using the radio without the pressures of flying. Your examiner will be sat in another room and will be acting as the air traffic controller as well as other agencies. You’ll be given a number of scenarios and tested on all the major aspects of using the radio including emergencies, airspace entries and service requests.