Fastest way to call API endpoints in android using retrofit2

Api.java

public class Api {
    public static Api instance = new Api();

    public Endpoints endpoints;
    
    private Api(){
        HttpLoggingInterceptor interceptor = new HttpLoggingInterceptor();
        interceptor.level(HttpLoggingInterceptor.Level.BODY);
        OkHttpClient client = new OkHttpClient.Builder().addInterceptor(interceptor)
                .build();

        Retrofit retrofit = new Retrofit.Builder()
                .baseUrl("https://jsonplaceholder.typicode.com/")
                .client(client)
                .addConverterFactory(GsonConverterFactory.create())
                .build();

        endpoints = retrofit.create(Endpoints.class);
    }

    public interface Endpoints{
        @GET("posts/{id}") // products/1?test=""
        Call<Post> getPost(@Path("id") int id);

        @GET("posts")
        Call<List<Post>> getPosts();

        @POST("posts")
        Call<ResponseBody> postPost(@Body Post post);
    }
}

build.gradle

dependecies{
   //retrofit for network calls
    implementation "com.squareup.retrofit2:retrofit:2.9.0"
    // use json to pojo: https://www.jsonschema2pojo.org/
    implementation "com.squareup.retrofit2:converter-gson:2.9.0"
    //for debugging with retrofit
    //for logging http request by retrofit
    implementation 'com.squareup.okhttp3:logging-interceptor:4.2.1'
}

MainActivity.java

public class MainActivity extends AppCompatActivity {

    public static final String TAG = "MainActivity->";
    ActivityMainBinding mVB;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        mVB = ActivityMainBinding.inflate(getLayoutInflater());
        setContentView(mVB.getRoot());
        Log.d(TAG, "onCreate: ");

        Api.Endpoints endpoints = Api.instance.endpoints;
        
        Call<Post> call = endpoints.getPost(1);
       /*call.enqueue(new Callback<Post>() {
           @Override
           public void onResponse(Call<Post> call, Response<Post> response) {
               if(response.isSuccessful() && response.body()!=null){
                   Post post = response.body();
                   Log.d(TAG, "onResponse: "+post);
               }else{
                   Log.e(TAG, "onResponse: error");
               }
           }

           @Override
           public void onFailure(Call<Post> call, Throwable t) {

           }
       });*/
        
        Post post = new Post(1, 1, "Tamim", "Tamim ehsan");
        Call<ResponseBody> call1 = endpoints.postPost(post);
        call1.enqueue(new Callback<ResponseBody>() {
            @Override
            public void onResponse(Call<ResponseBody> call, Response<ResponseBody> response) {
                if(response.isSuccessful() && response.body()!=null){
                    try {
                        String body = response.body().string();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }

            @Override
            public void onFailure(Call<ResponseBody> call, Throwable t) {

            }
        });
    }
}

Post.java

import com.google.gson.annotations.Expose;
import com.google.gson.annotations.SerializedName;

public class Post {

    @SerializedName("userId")
    @Expose
    private Integer userId;
    @SerializedName("id")
    @Expose
    private Integer id;
    @SerializedName("title")
    @Expose
    private String title;
    @SerializedName("body")
    @Expose
    private String body;

    public Post(Integer userId, Integer id, String title, String body) {
        this.userId = userId;
        this.id = id;
        this.title = title;
        this.body = body;
    }

    public Integer getUserId() {
        return userId;
    }

    public void setUserId(Integer userId) {
        this.userId = userId;
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getBody() {
        return body;
    }

    public void setBody(String body) {
        this.body = body;
    }

    @Override
    public String toString() {
        return "Post{" +
                "userId=" + userId +
                ", id=" + id +
                ", title='" + title + '\'' +
                ", body='" + body + '\'' +
                '}';
    }
}