However, you can also enter the bank details under the Description box of the check, so it will be included once printed. Please the screenshot attached for your reference:
Lastly, know that we always aim to help our customer to run their business easier. That said, our developers are constantly uncovering and considering new ways to cope with your needs. To be updated with our latest news and enhancements, please visit our QuickBooks Online Blog.
Should you have any other questions about QuickBooks, just let me know and I'd be pleased to help. Have a nice day!