New Mail(Android API)

Unable to access API new mail.

I use Retrofit to work with the network.

This is how I form the interface:

@FormUrlEncoded
@POST("/v2.0/json")
Call<NovaPochtaSityModel> getSity(@Field("apiKey") String key, @Field("modelName") String modelName, @Field("calledMethod") String calledMethod);

Well, then I turn to the server:

Call<NovaPochtaSityModel> call = api.getSity("key","InternetDocument","getDocumentList");
    call.enqueue(new Callback<NovaPochtaSityModel>() {
        @Override
        public void onResponse(Call<NovaPochtaSityModel> call, Response<NovaPochtaSityModel> response) {
            Log.d("TAG", "Success");
        }

        @Override
        public void onFailure(Call<NovaPochtaSityModel> call, Throwable t) {
            Log.d("TAG", "Fail");
        }
    });

Well, actually initialization:

Gson gson = new GsonBuilder().create();
    Retrofit retrofit = new Retrofit.Builder()
            .client(getUnsafeOkHttpClient())
            .baseUrl("https://api.novaposhta.ua")
            .addConverterFactory(GsonConverterFactory.create(gson))
            .build();
    API api = retrofit.create(API.class);

In response, I catch:

java.net.SocketTimeoutException: failed to connect to api.novaposhta.ua/185.128.233.69 (port 8883) after 10000ms

I increased the waiting time to 60 seconds, but it didn't help. And there is not so much data to pull them for more than a minute

UPD: