laravel passport 代理出错

代码

$response = $this->http->request('post', 'http://ruicao.io/api/oauth/token', [
            'form_params' => [
                'username'      => '[email protected]',
                'password'      => '123456',
                'client_id '    => '1',
                'client_secret' => 'PXrLBReX7gPjheLcfXJzF223GnI1uDHv8xw3SsZB',
                'grant_type'    => 'password',
                'scope'         => '',
            ]
        ]);

报错信息

Client error: `POST http://ruicao.io/api/oauth/token` resulted in a `400 Bad Request` response:\n
{"error":"invalid_request","message":"The request is missing a required parameter, includes an invalid parameter value,  (truncated...)\n

提示缺少参数，已经将值都写在 form_params 里了