Currently, the ability to generate bank statements in QuickBooks Online (QBO) is unavailable. You can go to your bank's website and get it manually as a workaround.
Once done, I highly suggest comparing the list of transactions on your bank statement with what's in QBO by simply reconciling them. Here's how:
Go to the Accounting menu at the left pane to get to the Reconcile page.
Click Get Started, then Let's do it.
Select the bank account in the Account drop-down.
Check the Last statement ending date and review the Beginning balance.
Enter the Ending balance and Ending date, then hit Start reconciling.