Thanks for getting back to us and providing a screenshot, ihtemamrentacart.

Based on your screenshot, I can see we are not in the upper part of the transaction in the account history. Let's scroll up until  we can see the Add button. 

However, if this won't fix the problem, we can try our recommended troubleshooting steps that can help the Add button back in the account history. 

There are times we encounter unusual behavior in software like QuickBooks. Storing a lot of files in the history folder can be the cause of the issue. 

First, we'll need to log in to your account using an incognito window. I'm adding the shortcut keys below depending on the browser you're using:

• For Google Chrome, you can press  Ctrl + Shift + N.
• For Mozilla Firefox and Internet Explorer, you can press  Ctrl + Shift + P.

After accessing QuickBooks through an incognito window, let's go back to the Bank Account History to check if you can now Add another transaction. If it works, you can clear the cache. This is to start your data fresh and help QuickBooks to work properly. Alternatively, you can use other supported browser in QBO.

Keep us posted on how the troubleshooting steps go. We're always here ready to help you more! Take care!