Good to see your post here, deon2.
Bank details can be added on your sales forms using the custom fields or footers in QuickBooks Online (QBO). You'll find the instructions for doing so below:
If you want to add the details as one of the custom fields:
If you want to add the details as footer:
I'm enclosing an article to help you know more about adding bank details to your invoices.
If you have follow-up questions or concerns, just let me know by leaving a reply below. Enjoy the rest of the day!