Back-end and Front-end to Insert into MySql database with node.js on remote server from Ionic2

Hello, I have to ask the previous question, because I’m not get result yet. If as local-host nodejs server I can use this code to insert into MySql database:

    app.get('/addpost1', (req, res) => {
        let post = {title:'Post One', body:'Post number one'};
        let sql = 'INSERT INTO posts SET ?';
        let query = db.query(sql, post, (err, result) => {
            if(err) throw err;
            console.log(result);
            res.send('Post 1 added...');
        });
    });

Or as web insert on remote server with: http: //webname/abc :

    app.get('/abc', function (req, res) {
    	var con1 = mysql.createConnection({
    	  host: "127.0.0.1",
    	  user: "username",
    	  password: "password",
    	  database : "databasename"
    	});
    
    	con1.connect(function(err) {
    	  if (err) throw err;
    	  con.query("INSERT INTO posts (body, title) VALUES ('string A1', 'string A2')", function (err, result, fields) {
    		if (err) throw err;
    	  });
    	});
     res.send('result[10].title');
    });

How to insert from my ionic2 application to MySql database on remote server with node.js. If I have to use code below, what should be a back-end code and front-end to pass inserted value to db. Also not quite sure, in headers.append('Access-Control-Allow-Origin', '*'); it is domain name or database local access: headers.append('Access-Control-Allow-Origin', 'localhost:3000');

    import { HttpClient, HttpParams } from '@angular/common/http';
    import { Injectable } from '@angular/core';
    import { Http, Headers, RequestOptions, Response } from '@angular/http';
    import { Observable } from 'rxjs/Observable';
    import { HttpClientModule } from '@angular/common/http';
    
    import 'rxjs/add/operator/toPromise';
    import 'rxjs/add/operator/map';
    import 'rxjs/add/operator/catch';
    
    @Injectable()
    export class RequestProvider {
    
      hostname: string = "http://192.168.0.55:3000";
    
      constructor(public http: HttpClient) {
        console.log('Hello RequestProvider Provider');
      }
    
       get(endPoint){
          let url = this.hostname + endPoint;
          var promise = new Promise((resolve,reject)=>{
              this.http.get(url).map((res)=> res.json())
              .subscribe(data => {
                resolve(data);
                console.log(data);
              })
          })
          return promise
        }
        post(endPoint,data){
          let url = this.hostname + endPoint;
          let headers = new Headers();
          headers.append('Access-Control-Allow-Origin', '*');  
          headers.append('Access-Control-Allow-Methods', 'POST, GET, OPTIONS, PUT');
          headers.append('Accept','application/json');
          headers.append('content-type','application/json');
            let options = new RequestOptions({ headers:headers});
          return new Promise((resolve,reject)=>{       
              this.http.post(url,JSON.stringify(data), options).subscribe(res => {resolve(res.json());
              }, (err) => {
                reject(err);
              });
          })
        }

Thank you

Advice would be helpful