Hello! Pilots can contact Tower when they are 27NM away from their destination airport. But it may be hard to coordinate with other controllers in Training Server unfortunately, usually the Approach will hand them to Tower when Tower has cleared them for the ILS Approach (Expert).
Anyway, I see that you are a potential candidate to be a candidate in Expert Server. Why don’t you give it a try to become an IFATC and has lesser chances to meet trolls/immature pilots. For more information, you can check this topic. We use Slack to coordinate between Tower, Ground, and Radar facilities
Edit : I see that you are not a Grade 3 yet. But if you are interested with this offer, you may want to contact one of the trainers to sharpen your skills before going to Grade 3 and applying to become an IFATC. Thanks @Marshall_Hilfman for the information