You can use Power Automate Desktop to run VBA for Excel Online

I created a video that demos how to use Power Automate Cloud and Desktop to trigger a VBA macro on a schedule in unattended mode on an Excel file resident on SharePoint Online (SPO).

You can use VBA to refresh an external data query. So, this means you can refresh an external data query for an Excel file resident on SPO.
Update : Microsoft has recently announced the part-enablement of Query Refreshing for Excel Online.