How to resolve error Code 403 from Cowin Public API in android studio?

Question

Here's the link to the Cowin Public API:

1. https://apisetu.gov.in/public/marketplace/api/cowin#/
2. https://cdn-api.co-vin.in/api/v2/admin/location/states

I have been trying to get the state details from the 2nd link in android studio using retrofit library. But every time I run the app it's showing error 403. Any help would be appreciated!! Adding my code below:

1. On create activity:

    Retrofit retrofit = new Retrofit.Builder().baseUrl("https://cdn-api.co-vin.in/api/").addConverterFactory(GsonConverterFactory.create()).build();

        CovidAPI covidAPI = retrofit.create(CovidAPI.class);

        Call<StateMainModel> call = covidAPI.getAllIndiaStates();

        call.enqueue(new Callback<StateMainModel>() {
            @Override
            public void onResponse(Call<StateMainModel> call, Response<StateMainModel> response) {
                if(!response.isSuccessful())
                {
                    Toast.makeText(getApplicationContext(),"Error!!Code: "+response.code()+response.toString(),Toast.LENGTH_SHORT).show();
                    tv.setText(response.toString());
                    return;
                }
                else
                {
                    StateMainModel stateMainModel = response.body();

                    int size = stateMainModel.getStates().size();

                    for(int i=0;i<size;i++)
                    {
                        stateList.add(stateMainModel.getStates().get(i).getState_name());
                    }

                    stateAutoCompleteTextView.setAdapter(stateAdapter);
                }

            }

            @Override
            public void onFailure(Call<StateMainModel> call, Throwable t) {
                Toast.makeText(getApplicationContext(),"Error!! Response: "+t.getMessage(),Toast.LENGTH_LONG).show();
            }
        });

2. API Interface

@GET("v2/admin/location/states")
    Call<StateMainModel> getAllIndiaStates();

3. StateMainModel Model Class

private ArrayList<StateIdNameModel> states;
    private Integer ttl;

    public StateMainModel() {
    }

    public StateMainModel(ArrayList<StateIdNameModel> states,Integer ttl) {
        this.states = states;
        this.ttl = ttl;
    }

    public ArrayList<StateIdNameModel> getStates() {
        return states;
    }

    public void setStates(ArrayList<StateIdNameModel> states) {
        this.states = states;
    }

    public Integer getTtl() {
        return ttl;
    }

    public void setTtl(Integer ttl) {
        this.ttl = ttl;
    }

Answer 1

Here's the Java Code that worked for me:

OkHttpClient client = new OkHttpClient();

        client = new OkHttpClient.Builder().addInterceptor(new Interceptor() {
            @Override
            public okhttp3.Response intercept(Interceptor.Chain chain) throws IOException {

                Request originalRequest = chain.request();
                Request requestWithUserAgent = originalRequest.newBuilder().header("User-Agent","Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.212 Safari/537.36").build();
                return  chain.proceed(requestWithUserAgent);


            }
        }).build();