I'd be happy to help you export your bank reconciliation in QuickBooks Online (QBO). Before I do, can you elaborate more on your concern? Are you trying to export a bank reconciliation page before reconciling it? This way, I can give you the right steps on how to do so.
However, if you're trying to export a reconciliation report, currently, we're unable to export it. Though, we can only print or save it in .PDF format.
Go to the Reports menu.
On the search bar, type Reconciliation Reports.
Click the Printer icon at the top of the report.
A new window will open and then click Print.
Select the Destination drop-down arrow to Save as PDF.