GetTicketCounts

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, 'https://www.example.com/includes/api.php');
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS,
    http_build_query(
        array(
            'action' => 'GetTicketCounts',
            // See https://developers.whmcs.com/api/authentication
            'username' => 'IDENTIFIER_OR_ADMIN_USERNAME',
            'password' => 'SECRET_OR_HASHED_PASSWORD',
            'ignoreDepartmentAssignments' => false,
            'includeCountsByStatus' => true,
            'responsetype' => 'json',
        )
    )
);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
$response = curl_exec($ch);
curl_close($ch);

$command = 'GetTicketCounts';
$postData = array(
    'ignoreDepartmentAssignments' => false,
    'includeCountsByStatus' => true,
);
$adminUsername = 'ADMIN_USERNAME'; // Optional for WHMCS 7.2 and later

$results = localAPI($command, $postData, $adminUsername);
print_r($results);

{
    "result": "success",
    "filteredDepartments": [
        1,
        2,
        3
    ],
    "allActive": 123,
    "awaitingReply": 100,
    "flaggedTickets": 15,
    "status": {
        "open": {
            "title": "Open",
            "count": 60
        },
        "answered": {
            "title": "Answered",
            "count": 23
        },
        "customerreply": {
            "title": "Customer-Reply",
            "count": 40
        },
        "closed": {
            "title": "Closed",
            "count": 4220
        },
        "onhold": {
            "title": "On Hold",
            "count": 10
        },
        "inprogress": {
            "title": "In Progress",
            "count": 0
        }
    }
}