guzzle-http-post-(json)

    $client   = new \GuzzleHttp\Client();
    $response = $client->post('http://xxx.com/api/login', [
        'json' => [
            'phone'      => "152xxxx1234",
            'password' => "123456",
        ]
    ]);

    $response = $client->post('http://xxx.com/api/login', [
        'form_params' => [
            'phone'      => "152xxxx1234",
            'password' => 123456,
        ]
    ]);