BinaryFileResponse in Laravel undefined

You may want to exclude headers or set different headers for file download requests by checking the header method exists in the returned Closure.

File download requests typically have the header method omitted from Closure.

public function handle($request, Closure $next)
{
    $handle = $next($request);

    if(method_exists($handle, 'header'))
    {
        $handle->header('Access-Control-Allow-Origin' , '*')
               ->header('Access-Control-Allow-Methods', 'POST, GET, OPTIONS, PUT, DELETE')
               ->header('Access-Control-Allow-Headers', 'Content-Type, Accept, Authorization, X-Requested-With, Application');
    }

    return $handle;
    
}

If you need to set headers for a file request (as other answer suggested) $handle->headers->set() can be used in an else condition:

public function handle($request, Closure $next)
{
    $handle = $next($request);

    if(method_exists($handle, 'header'))
    {
        // Standard HTTP request.

        $handle->header('Access-Control-Allow-Origin' , '*');

        return $handle;
    }

    // Download Request?

    $handle->headers->set('Some-Other-Header' , 'value')

    return $handle;
    
}

The problem is that you're calling ->header() on a Response object that doesn't have that function (the Symfony\Component\HttpFoundation\BinaryFileResponse class). The ->header() function is part of a trait that is used by Laravel's Response class, not the base Symfony Response.

Fortunately, you have access to the headers property, so you can do this:

$response = $next($request);

$response->headers->set('Access-Control-Allow-Origin' , '*');
$response->headers->set('Access-Control-Allow-Methods', 'POST, GET, OPTIONS, PUT, DELETE');
$response->headers->set('Access-Control-Allow-Headers', 'Content-Type, Accept, Authorization, X-Requested-With, Application');

return $response;