Magic Keys is not directly compatible with Mac OS. We have many people using it on Mac by virtualizing Windows with software like Parallels Desktop or Virtual Box or VMWare Fusion or Boorcamp.
Metatrader itself is not compatible with Mac. The Mac version of MT works on MAC because it uses a Windows simulator underneath. Saving and restoring the machine state will get you the same result as if using a normal app.
You can use the following videos to install it using virtual box:
Magic keys (videos on the download page on our website)
Free: virtual box or vmware fusion or bootcamp
Magic Keys Team