1. login root account
2. open terminal
3. command: sudo -i
4. command: cd /var/www/
5. command: nano getmac.php
6. following copy and pate to getmac.php

<?php
header('Access-Control-Allow-Origin: *');
$Result = array("STATUS" => "", "MAC_ADDR" => "");

function ReadMacAddressUbuntuCommand() {
    global $Result;
    if (strtoupper(substr(PHP_OS, 0, 3)) === 'LIN') {
        $ifconfigResult = shell_exec("/sbin/ifconfig -a | grep -o -E '([0-9A-Fa-f]{2}:){5}([0-9A-Fa-f]{2})'");
        
        if ($ifconfigResult != null) {
            $macAddress = trim($ifconfigResult);
            if ($macAddress != "") {
                $Result["STATUS"] = "OK";
                $Result["MAC_ADDR"] = $macAddress;
            }
        } else {
            $Result["STATUS"] = "CANNOT_GET_MAC_ADDRESS";
        }
    } else {
        $Result["STATUS"] = "NOT_UBUNTU_SYSTEM";
    }
}

if (isset($_REQUEST["CMD"]) && $_REQUEST["CMD"] == "GETMAC") {
    // First test read a fixed txt file
    $FixMacAddressFile = "./StationMacAddress.txt";
    $MacAddressFile = fopen($FixMacAddressFile, "r");
    if ($MacAddressFile) {
        $MacAddressFixed = rtrim(fread($MacAddressFile, filesize($FixMacAddressFile)));
        fclose($MacAddressFile);
        if (preg_match('/^(?:(?:[0-9a-f]{2}[\:]{1}){5}|(?:[0-9a-f]{2}[-]{1}){5}|(?:[0-9a-f]{2}){5})[0-9a-f]{2}$/i', $MacAddressFixed) == 1) {
            $Result["STATUS"] = "OK";
            $Result["MAC_ADDR"] = $MacAddressFixed;
        } else {
            ReadMacAddressUbuntuCommand();
        }
    } else {
        ReadMacAddressUbuntuCommand();
    }
}

echo json_encode($Result);
?>


7. Press keyboard: Ctrl + X             >>>>>   enter : Y      >>>>>>>>>>> Press : Enter 
8. Commnd: ip addr show (this is check MAC address ) f4:8e:38:d6:88:5f
9. Copy the MAC address
10. Command : nano StationMacAddress.txt
11. paste the mac address StationMacAddress.txt than save and exit like step 7 
12. Command: service apache2 restart
13. open browser and input this url localhost:8888/getmac.php?CMD=GETMAC in address bar, if success and will show the mac address