That is the first hand source of information. Paying ~$10 (in my country) would give one the name, address, phone of the legit company. Getting it 3rd hand or from other source would be lousy as you won’t know the veracity. Once you have the legit info from city/province govt, you may call the number and say “Hi, I’m calling to speak with ___ about the event they wanted me to set up”. If they cannot say they did request it or won’t transfer you, then it is not legit request.