This is a great observation, I'll try give you some tips on how you can achieve this.
You are able to create one within the Chart of Accounts.
Now you are able to import your CSV file into the newly created account.
You should now be able to see a new bank account in your Banking tab with the transactions you just imported over.
Let me know if you still needed any assistance!
Thank you for following up with us.
If transactions have not been added to your QuickBooks Online, but only showing under the "For Review" session, by disconnecting the bank feed, those transactions will also be removed.
You can also manually exclude unwanted transactions. Please visit the link below for more details:
Thank you and please let us know if you require any additional assistance.