问cURL错误3：<url>格式错误- Laravel 5.6

EN

cURL error 3: <url> malformed (see http://curl.haxx.se/libcurl/c/libcurl-
errors.html)

APP_URL=http://acpapi.staging

$user = $this->create($request->all());
            $http = new Client;
            // return $http->post(env('APP_URL'));
            $response = $http->post(env('APP_URL') . '/oauth/token', [
                'form_params' => [
                    'grant_type' => 'password',
                    'client_id' => env('PASSWORD_CLIENT_ID'),
                    'client_secret' => env('PASSWORD_CLIENT_SECRET'),
                    'username' => $request->get('email'),
                    'password' => $request->get('password'),
                    'remember' => false,
                    'scope' => '',
                ],
            ]);
return $this->successResponse([
                'token_data' => json_decode($response->getBody()),
                'user' => [
                    'email' => $user->email
                ]
            ]);

"cURL error 3: <url> malformed (see http://curl.haxx.se/libcurl/c/libcurl-errors.html)"