Is there any activity to create a new list in SharePoint using an already existing app template available in SharePoint?
Not currently possible using the activities, but this is how that’d work if you were to use the UI:
Is it possible using API without using UI?
Can we automate it using API without using UI? Is there any particular reason that this activity is not included in existing SharePoint activities?
I think you can use the sharepoint scope to return a valid client context and then invoke some code that can create your list. The code would be similar to this: Create A Task List In SharePoint 2013 Using CSOM (this code creates a list from the task list template)
If you want to “clone” an existing list, code similar to this should be used sharepoint online - replicating the list with same fields but different list name using csom - SharePoint Stack Exchange