Thank you for posting here in the Community, @ACCANO.
I'm here to provide clarification on the process of adding notes in QuickBooks Online
The Notes option is currently unavailable in the modern view. However, you’ll be able to see them if you’re using the old layout. Simply click the Switch to classic viewbutton to return to the previous reporting experience.
Moreover, the ability to add notes in the new design is undeniably convenient and would benefit not just you, but other users as well.
That being said, let's send this request to our Product Developers so they can consider adding this in future updates. Rest assured, they're constantly working to help you experience the best of QuickBooks.
Here's how to send your feedback:
Go to the Gear icon located in your top right corner.