gimana cara melakukan security di CI

gan ane kan bikin page pemabayaran dan itu berdasarkan id ya detailny pas muncul tp ketika user lain mengganti urlny itu mereka juga bisa melihat pembelian user lain jd gimana ya carany user lain itu ga bisa melakukan pembayaran punya user yang lainny?

ini kode fungsi pembayaranny

public function pembayaran($id)
    {
        $data['title'] = 'Pembayaran';

        $data['user'] = $this->db->get_where('user', ['id' => $this->session->userdata('email_id')])->row_array();
        $data['user'] = $this->db->get_where('user', ['firstName' => $this->session->userdata('author')])->row_array();
        $data['user'] = $this->db->get_where('user', ['email' => $this->session->userdata('email')])->row_array();
        $data['order_brg'] = $this->db->get_where('order_brg', ['id_order' => $this->session->userdata('id_order')])->row_array();

        $this->load->model('PostModel', 'post');
        $data['order'] = $this->post->getTotal($id);

        $data['nama_brg'] = $this->db->get('barang')->result_array();
        $data['kode'] = $this->db->get('stats')->row_array();

        $this->form_validation->set_rules('pelanggan', 'Nama Anda', 'required');
        $this->form_validation->set_rules('alamat', 'Alamat', 'required');
        $this->form_validation->set_rules('nm_barang', 'Nama Barang', 'required');
        $this->form_validation->set_rules('jumlah', 'Jumlah', 'required');

        if ($this->form_validation->run() == false) {

            $this->load->view('templates/user-header', $data);
            $this->load->view('templates/user-sidebar', $data);
            $this->load->view('templates/user-topbar', $data);
            $this->load->view('user/pembayaran', $data);
            $this->load->view('templates/user-footer');
        } else {

            $id = $this->input->post('id_order');
            $pelanggan = $this->input->post('pelanggan');
            $alamat = $this->input->post('alamat');
            $jumlah = $this->input->post('jumlah');
            $tgl = $this->input->post('tgl_kirim');
            $nm_barang = $this->input->post('nm_barang');
            $id_plg = $this->input->post('id_pelanggan');
            $status = $this->input->post('status');

            $data = [
                'pelanggan' => $pelanggan,
                'alamat' => $alamat,
                'jumlah' => $jumlah,
                'tgl_kirim' => $tgl,
                'nm_barang' => $nm_barang,
                'id_pelanggan' => $id_plg,
                'status' => $status,

            ];

            $this->db->insert('order_brg', $data);
            $this->session->set_flashdata('message', '<div class="alert alert-success" role="alert">Please wait admin approve your post</div>');
            redirect('user/order');
        }
    }