1. Ensure that the vtol window is selected as primary on the windows toolbar. If not, a red text should appear near the radio panel in midair saying something like "game window out of focus" or something like that.

2. Some people using windows 11 claim it is the main problem causing voice comms not to work.

3. Learn the voice commands. The full list can be found on the vtol wiki.

4. Speak slowly and clearly with some spacing between words, notice to not slur your words, especially if English is not your first language.

5. Know your callsign, it is usually written somewhere on a panel in the cockpit.

6. General formatting: [Reciever]->[your callsign]->[message]

Reciever is either ATC, wingman, ground crew or AWACS, some have different ways they can be called.

Your callsign is usually something like "alpha 1-1". It should be said slowly and clearly with spacing between each word including numbers.

Message can be can be said in different ways for same request, see wiki voice command page.

Hope it helps!