Full Code

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Data.OleDb;
using System.Data.SqlClient;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace Insert_Test
{
    public partial class Form1 : Form
    {
        private OleDbConnection connection = new OleDbConnection();
        string database = Path.GetDirectoryName(System.Reflection.Assembly.GetEntryAssembly().Location) + "\\password.accdb";


        public Form1()
        {
            InitializeComponent();
            connection.ConnectionString = @"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + database + ";Jet OLEDB:Database Password=1711223ms;";
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            MessageBox.Show("Please input your password here", "Password Request Instrucion", MessageBoxButtons.OK, MessageBoxIcon.Asterisk);
        }

        private void pass_btn_Click(object sender, EventArgs e)
        {
            try
            {
                connection.Open();

                OleDbCommand command = new OleDbCommand();
                command.Connection = connection;
                command.CommandText = "INSERT INTO Password ([password]) VALUES('" + password.Text + "')";

                command.ExecuteNonQuery();
                MessageBox.Show("Success");

                connection.Close();
            }
            catch (Exception ex)
            {
                MessageBox.Show(Convert.ToString(ex));
            }
        }
    }
}