JSON formatting with the extra nameValuePair inside retrofit request

Question

I am Sending one request to the server with the help of retrofit. Inside the body of request I have to pass JSON. From the POJO what I am getting in the form of JSON is below

    { 
        "id": "22",
        "firstname": "abcd",
        "lastname": "pqrl",
        "mail": "abcd@gmail.com",
        "access": true,
        "has_access": true,
        "iduser": 17,
        "accepted": false
    } 

instead of this what I have to send to the body is below

{
    "user": {
        "id": "22",
        "firstname": "abcd",
        "lastname": "pqrl",
        "mail": "abcd@gmail.com",
        "access": true,
        "has_access": true,
        "iduser": 17,
        "accepted": false
    }
}

So what I have done is I have created JSONObject

final JSONObject parent = new JSONObject();

        try {
            parent.put("user",**myPojoJson**);
        } catch (JSONException e) {
            e.printStackTrace();
        }

With this I am able to get the JSON format I want but there is some extra value added to the JSON which is nameValuePair

{
  "nameValuePairs": {
    "User":  { 
        "id": "22",
        "firstname": "abcd",
        "lastname": "pqrl",
        "mail": "abcd@gmail.com",
        "access": true,
        "has_access": true,
        "iduser": 17,
        "accepted": false
    }
  }
}

I checked online there are solution to use Use com.google.gson.JsonObject instead of org.json.JSONObject. But Is there any way I can still use JSONObject and able to achieve what I want ?

EDIT with adding POJO

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

public class Vishvendu {

@SerializedName("id")
@Expose
private String id;
@SerializedName("firstname")
@Expose
private String firstname;
@SerializedName("lastname")
@Expose
private String lastname;
@SerializedName("mail")
@Expose
private String mail;
@SerializedName("access")
@Expose
private Boolean access;
@SerializedName("has_access")
@Expose
private Boolean hasAccess;
@SerializedName("iduser")
@Expose
private Integer iduser;
@SerializedName("accepted")
@Expose
private Boolean accepted;

public String getId() {
return id;
}

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

public String getFirstname() {
return firstname;
}

public void setFirstname(String firstname) {
this.firstname = firstname;
}

public String getLastname() {
return lastname;
}

public void setLastname(String lastname) {
this.lastname = lastname;
}

public String getMail() {
return mail;
}

public void setMail(String mail) {
this.mail = mail;
}

public Boolean getAccess() {
return access;
}

public void setAccess(Boolean access) {
this.access = access;
}

public Boolean getHasAccess() {
return hasAccess;
}

public void setHasAccess(Boolean hasAccess) {
this.hasAccess = hasAccess;
}

public Integer getIduser() {
return iduser;
}

public void setIduser(Integer iduser) {
this.iduser = iduser;
}

public Boolean getAccepted() {
return accepted;
}

public void setAccepted(Boolean accepted) {
this.accepted = accepted;
}

}

This is how I am adding body to the request

interface LoginApi {
        @PUT("user/abcd")
        Call<abcdResponse> updateabcdStatus(@Body JSONObject parent);
    }