laravel passport oauth：客户端错误：`POST http：//127.0.0.1：8000 / oauth / token`导致'400 Bad Request`响应：(

Question

我在Laracast的本地主机窗口上复制了Taylor Otwell的前端/后端护照示例：后端运行127.0.0.1:8000，前端运行127.0.0.:8080当我尝试客户端api调用时 - 127.0.0.1:8080/回调我得到这个：

ClientException in RequestException.php line 111:
Client error: `POST http://127.0.0.1:8000/oauth/token` 
resulted in a `400 Bad Request` response:
{"error":"invalid_request","message":"The request is missing a required
 parameter, includes an invalid parameter value, (truncated...)

而这个细节：

at Client request('post','http://127.0.0.1:8000/oauth/token',
array('form_params' => array('grant_type' => 'authorization_code',
'client_id' => 3, 
'client_secret' =>'23GCROVkVMtQqKsJKmx2xPojiDU4TOOe3ZMvKvQh', 
'redirect_uri' =>'http://127.0.0.1:8080/callback', 'code' => null),
 'synchronous' =>true)) in Client.php line 87 

at Client->__call('post', array('http://127.0.0.1:8000/oauth/token',
 array('form_params' =>array('grant_type' => 'authorization_code',
'client_id' => 3, 
'client_secret' =>'23GCROVkVMtQqKsJKmx2xPojiDU4TOOe3ZMvKvQh',
'redirect_uri' => 'http://127.0.0.1:8080/callback', 'code' => null))))in web.php line 3

这是相关代码：

Route::get('/callback', function () {

    $query = http_build_query([
        'client_id' => 3,
        'redirect_uri' => 'http://127.0.0.1:8080/callback',
        'response_type' => 'code',
        'scope' => ''
    ]);

    return redirect('http://127.0.0.1:8000/oauth/authorize?'.$query);
});

Route::get('/callback', function (Request $request) {
$http = new GuzzleHttpClient;

$response = $http->post('http://127.0.0.1:8000/oauth/token',[
    'form_params' => [
        'grant_type' => 'authorization_code',
        'client_id' => 3,
        'client_secret' => '23GCROVkVMtQqKsJKmx2xPojiDU4TOOe3ZMvKvQh',
        'redirect_uri' => 'http://127.0.0.1:8080/callback',
        'code' => $request -> code,
    ],
]);

return json_decode((string) $response->getBody(),true);

感谢任何建议

（fyi，我在用户模型中设置了HasApiTokens以及所有其他要求。我想知道它是否与尝试在本地主机上运行laravel客户端和laravel后端有关）。