While creating a sale order, partner_id is required. Specify the product using product_id. Provide the id of the product and customer instead of using the name directly. For example, refer to the below code:

sale_order = self.env['sale.order'].create({

            'partner_id': self.partner_id.id,

            'order_line': [(0, 0, {

                'product_id': self.env['product.product'].search([('name', '=', 'test')], limit=1).id,

                'name': 'test',

                'product_uom_qty': 1,

                'price_unit': 3.00,

            })],

        })

Hope it helps