How real-time apply works in logical standby oracle?
Does archived redo logs required for logical standby or not? 
  Yes, it does. 


https://docs.oracle.com/cd/B19306_01/server.102/b14239/create_ls.htm#g105412

The archived redo logs (archivelogs, commonly) contain SQL statements to apply the changes being made to the database, as well as SQL statements to undo the work if a rollback occurs later on the primary's activity.