How do we export an event from Sharepoint calendar in office 365

Hello,

I am trying to export a calendar event as a .ics file from Sharepoint calendar. With SP2013 we can use :

/sites/SiteName/_vti_bin/owssvr.dll?CS=109&Cmd=Display&List=ListID&CacheControl=1&ID=ITEMID

but when i try to use the above url for SP online i get a 'Cannot complete this action error'.

How do we implement this in Sharepoint online?

Thanks