Can i use route ID for Link template 'edit-form' for entity type?
The tutorial is from 2014. Since then the link templates have changed from route to path. See change record:

Previous link template format

   links = {
     "canonical" = "entity.node.canonical",
     "edit-form" = "entity.node.edit_form",
     "delete-form" = "entity.node.delete_form",
   }



New link template format

After the change, the path is used.

   links = {
     "canonical" = "/node/{node}",
     "edit-form" = "/node/{node}/edit",
     "delete-form" = "/node/{node}/delete",
   }