You'll have to create a template, provide a business name and tick the box on the customer form styles page for it to show on your invoice. briseida-ayala-m.
To do this, you can follow the steps below.
After that, you can go to the actual invoice and use the template.
Lastly, you can go to the Other preferences tab section to change your date format.
Please check this article for more information: Customise Invoices, Estimates, And Sales Receipts In QuickBooks Online.
For future reference, you can email sales form to your customer after you've customised them.
Please touch base with us if you have any other concerns about customising sales form. We'll always be around to help you anytime.