Hey David,

Warning says, there might be some issue with the company_id or currency_id though its getting filled. Try passing the company_id and currency_id to the dict.

order_line.sudo().create([{'product_id': itemId,
'product_uom_qty': quantity,
'order_id': orderId,
'company_id': lambda self: self.env.user.company.id,
'currency_id': lambda self: self.env.company.currency_id.id
}])

Thanks & Regards,

Email: odoo@aktivsoftware.com

Skype: kalpeshmaheshwari