Bernau missiles

How in the ever loving hell do I fire the damned missiles, I aim at ever damn plane that comes into range (under 3.5k or so I am told) occasionally the green circle will turn red and get a solid tone but then… I have hit 5 and any other key related to locks and firing and still no missile fire.
I feel like I wasted my time even getting this boat the guns are ok I guess a little under powered imho, but the missiles were the selling point and right now useless to me if I can’t get them to fire.

You wasted your time playing ships in the first place the mobile version of warthunder is where the ship dev team went mostly it seems

I have shit eye sight and fat fingers so mobile is not for me, even with a zfold I cant see shit, and most tablets cant do mobile games like WT. PCMR is where I live.