The option to add a column in the Journal Entry page is unavailable. It would be a great feature to have inside QuickBooks Online (QBO), and we recommend sending a request to our Product Development Team. This way, they can review your suggestion and consider adding it in future updates. Here's how:
Access your QuickBooks Online company.
On the top right-corner, click the Gear icon.
Select Feedback and then enter your comments or product suggestions.