I'm trying to fill customer and order_line information in the order view, Odoo always creates a new record. I simply want to fill it out so it can be edited by the user before creating record. please help me.

Below is my code.

from odoo import fields, models, api

class SaleOrder(models.Model):
    _inherit = 'sale.order'
    shopee_id = fields.Char(string='Shopee Id')

    def test_button_function(self):
        dump_name = "Contacts_name_test_FULL"  # in feature, it get from api
        val = self.env['res.partner'].search_read([('name', '=ilike', dump_name)])
        for record in self:
            record.partner_id = val[0]['id']
            self.onchange_partner_id()

            dump_id = 1  # in feature, it can be replace by search by name get from api
            order_line_item = self.env['sale.order.line'].browse([dump_id])
            record.order_line = order_line_item