Ok, often during flights I get notified to contact “Approach/Tower on frequency *.” I click on the communication button, but the Approach/Tower is not in the list of available frequencies, but when I go to the map and click on the airport ID it shows me something like what is shown in the following screenshots of KJFK
I see the ATC controllers and I also see the Tune button, however when I click on it, nothing happens, it will not tune me into the frequency. The tune button seems to be blocked out. How can I tune into a frequency when it is not listed.