in show page activity pass the object of NewLineService which you have created.
Inside the show page activity you will see object to pass in the drop down select new line service.
The error is thrown because the page is expecting a type of object, on which a data view can either take input or show the inputs Avilable, so for this ,what you can do is, in the microflow that you created there is a show page activity,
In that show page activity, pass the object you just created through create activity.
Hope it helps!