Hello there, @chaiguan_tee.
I'd like to help you right now about invoices in QuickBooks Online. However, I still need to gather more details about it. Can you share with me the specific error, message or anything you experience when creating an invoice? This way, I can gather information about it and provide you the best resolution. Any additional details you'd share are much appreciated.
You'll want to check out these links for more guidance:
I'm always here to help you if you have any other concerns about QuickBooks transactions. You can leave the details in your reply and I'll answer them for you. Keep safe and have a great weekend ahead, chaiguan_tee.
