It seems there's an error because I'm using the custom tag [n.º de Factura a clientes] but it just doesn't work. All other custom fields like the client name are working fine. Here's an screenshot of the problem.
I'm using the spanish version.
Hi Henry Silva,
Let me share some information with you about custom invoice in QuickBooks Online.
You'll have an option to import your own invoice template in QuickBooks. However, it may not follow the mapping when using another language since the default language for the custom invoice is English.
For a more detailed information about using customized invoice template, you can read this article: Uploading Invoice Template in QuickBooks.
Don't hesitate to let me know if you have further questions or clarifications. I'll be here to help you.