Thanks for posting in the Community! If the details on the authorisation form you've submitted is incorrect, you can disconnect it to cancel your application.
Here's how:
Go to Banking tab.
Select the tile for the bank account that is pending authorisation.
Select the pencil ✎ icon, then select Edit account info.
In the Account window, select the Disconnect this account on save checkbox. Note: If QuickBooks is downloading new transactions, you won't see this option. Wait a few minutes for the update to finish and try again.
Select Save and Close.
The bank account will disappear from the Banking screen.