You can find below the instruction to find your MAC address depending on your operative system (Mac or Windows).
Open Terminal (found in Applications → Utilities → Terminal) and type:
networksetup -listallhardwareports
After pressing enter you should see a list of information like in the image below:
The WiFi MAC address is the Ethernet Address of the Hardware Port Wi-Fi (ac:de:48:00:11:22 in the example image).
Open Command line (you can find it by searching for "cmd" in the Start menu) and type:
getmac /v
After pressing enter you should see a list of information like in the image below:
The WiFi MAC address is the Physical Address for the Connection Name Wi-Fi row (00-1A-2B-3C-4D-5E in the example image).