我正在尝试登录用户和我使用的网络改型2，但我从服务器收到空响应，虽然我已经测试了 Postman 的api，它显示有响应，但无法在我的应用程序中获取响应。我无法得到这个错误的原因，我一直在努力解决这个问题。
这里是一个api url
这是一个apihttp://www.gurgaonhomeo.in/api_server/login 你可以在哪里查看回复email=digi@gmail.com 密码=digi1234
下面是我的堆栈跟踪：

java.lang.NullPointerException: Attempt to invoke interface method 'java.lang.Object java.util.List.get(int)' on a null object reference

这是我的api响应：

{
"data": [
    {
        "id": "7",
        "username": null,
        "mobile": "1254785698",
        "email": "digi@gmail.com",
        "image": "https://example.com",
        "created_date": "2020-11-06",
        "password": "dasdad324adad245435sffs34535",
        "name": "Digi",
        "address": "Hsbdbshbd",
        "homoeo_practioner": "Yes"
    }
],
"status": true,
"code": 200
}

我使用过的这些库：

implementation 'com.squareup.retrofit2:retrofit:2.5.0'
implementation 'com.squareup.retrofit2:converter-gson:2.5.0'

loginrespose.java文件

public class LoginResponse {

@Expose
@SerializedName("code")
private String code;

@Expose
@SerializedName("data")
private List<LoginRes> data;

@Expose
@SerializedName("status")
private String status;

public String getCode() {
    return code;
}

public void setCode(String code) {
    this.code = code;
}

public List<LoginRes> getData() {
    return data;
}

public void setData(List<LoginRes> data) {
    this.data = data;
}

public String getStatus() {
    return status;
}

public void setStatus(String status) {
    this.status = status;
}
}

登录.java

public class LoginRes {

@SerializedName("address")
@Expose
private String address;

@SerializedName("created_date")
@Expose
private String createdDate;

@SerializedName("email")
@Expose
private String email;

@SerializedName("homoeo_practioner")
@Expose
private String homoeoPractioner;

@SerializedName("id")
@Expose
private String id;

@SerializedName("image")
@Expose
private String image;

@SerializedName("mobile")
@Expose
private String mobile;

@SerializedName("name")
@Expose
private String name;

@SerializedName("password")
@Expose
private String password;

@SerializedName("username")
@Expose
private String username;

public String getAddress() {
    return address;
}

public void setAddress(String address) {
    this.address = address;
}

public String getCreatedDate() {
    return createdDate;
}

public void setCreatedDate(String createdDate) {
    this.createdDate = createdDate;
}

public String getEmail() {
    return email;
}

public void setEmail(String email) {
    this.email = email;
}

public String getHomoeoPractioner() {
    return homoeoPractioner;
}

public void setHomoeoPractioner(String homoeoPractioner) {
    this.homoeoPractioner = homoeoPractioner;
}

public String getId() {
    return id;
}

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

public String getImage() {
    return image;
}

public void setImage(String image) {
    this.image = image;
}

public String getMobile() {
    return mobile;
}

public void setMobile(String mobile) {
    this.mobile = mobile;
}

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public String getPassword() {
    return password;
}

public void setPassword(String password) {
    this.password = password;
}

public String getUsername() {
    return username;
}

public void setUsername(String username) {
    this.username = username;
}
}

API服务.java

@POST("login")
@FormUrlEncoded
Call<LoginResponse> logUser(@Field("email") String email,
                            @Field("password") String password);

登录.java

private void go(String  mail,String pwd){

    Retrofit retrofit = RetrofitClient.getInstance();
    ApiService apiService = retrofit.create(ApiService.class);

    apiService.logUser(mail,pwd).enqueue(new Callback<LoginResponse>() {
        @Override
        public void onResponse(Call<LoginResponse> call, Response<LoginResponse> response) {

            if(response.isSuccessful()){
                prg.dismiss();
               List<LoginRes> res = response.body().getData();
             Toast.makeText(getApplicationContext(),res.get(0).getEmail(),Toast.LENGTH_SHORT).show();
            }
        }

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

            prg.dismiss();
            Toast.makeText(getApplicationContext(),t.getMessage(),Toast.LENGTH_SHORT).show();
        }
    });
}

有人请让我知道为什么我从服务器得到空响应或我做错了什么。任何帮助将不胜感激。
谢谢