My problem is that when response is successful, i am getting response. But if response is not success, I am not getting any response in body, it's null. In case of any error like 404, 500 response is null. I am a beginner.
void sendMessage(){
    String user_id = sessionManager.getPreferences(getActivity(), "user_id");
    String message = binding.inputMessage.getText().toString();
    String api_key = "954f011a-ab85-42e";
    String secret_key = "v7FTQC&Cppbukk";
    if (message.isEmpty()){
        binding.inputMessage.setError("Please write your message");
        binding.inputMessage.requestFocus();
    }else {
        binding.inputMessage.setError(null);
        APIService service = RetrofitInstance.getRetrofitInstance().create(APIService.class);
        Call<ContactUsModel> call = service.sendMessage(user_id, message, api_key, secret_key);
        progressDialog.setMessage("Sending");
        progressDialog.show();
        call.enqueue(new Callback<ContactUsModel>() {
            @Override
            public void onResponse(Call<ContactUsModel> call, Response<ContactUsModel> response) {
                progressDialog.dismiss();
                ContactUsModel model = response.body();
                if (response.code() == 201){
                    if (model.getSuccess() == 1){
                        binding.inputMessage.setText("");
                        Toast.makeText(getActivity(), model.getMessage(), Toast.LENGTH_SHORT).show();
                    }
                }else{
                   //Toast.makeText(getActivity(), response.body().toString(), Toast.LENGTH_SHORT).show();
                    Log.e("responcebody" , response.body().toString());
                }
            }
            @Override
            public void onFailure(Call<ContactUsModel> call, Throwable t) {
                progressDialog.dismiss();
                Toast.makeText(getActivity(), t.getMessage(), Toast.LENGTH_SHORT).show();
            }
        });
    }
}
My Model is below in which i am getting responce, parameters name are totally correct
            package com.example.miinterest.model;
        
        import com.google.gson.annotations.SerializedName;
        
        public class ContactUsModel {
            @SerializedName("success") private int success;
            @SerializedName("message") private String message;
        
            public int getSuccess() {
                return success;
            }
        
            public void setSuccess(int success) {
                this.success = success;
            }
        
            public String getMessage() {
                return message;
            }
        
            public void setMessage(String message) {
                this.message = message;
            }
        }
And Api Call Method. I created a method and calling API from here
               @FormUrlEncoded
            @POST("addContactUsQuery")
            Call<ContactUsModel> sendMessage(
                    @Field("user_id") String user_id,
                    @Field("message") String message,
                    @Header("api_key") String api_key,
                    @Header("secret_key") String secret_key
            );

 
    