Render xml with ApplicationRender.render?

We render an xml.builder template with an ApplicationRender in a test for a task

ApplicationController.render(
      :template => 'sitemap/show',
      :locals => { tutorials: tutorials}
    )

But an error occurs that is

 NoMethodError:
       private method `format' called for "sitemap/show":String
       Did you mean?  form_tag
     # /home/kireto/.rvm/gems/ruby-2.7.4/gems/actionview-6.1.6/lib/action_view/renderer/template_renderer.rb:9:in `render'
     # /home/kireto/.rvm/gems/ruby-2.7.4/gems/actionview-6.1.6/lib/action_view/renderer/renderer.rb:61:in `render_template_to_object'
     # /home/kireto/.rvm/gems/ruby-2.7.4/gems/actionview-6.1.6/lib/action_view/renderer/renderer.rb:29:in `render_to_object'
     # /home/kireto/.rvm/gems/ruby-2.7.4/gems/actionview-6.1.6/lib/action_view/rendering.rb:117:in `block in _render_template'
     # /home/kireto/.rvm/gems/ruby-2.7.4/gems/actionview-6.1.6/lib/action_view/base.rb:273:in `in_rendering_context'
     # /home/kireto/.rvm/gems/ruby-2.7.4/gems/actionview-6.1.6/lib/action_view/rendering.rb:116:in `_render_template'
     # /home/kireto/.rvm/gems/ruby-2.7.4/gems/actionpack-6.1.6/lib/action_controller/metal/streaming.rb:218:in `_render_template'
     # /home/kireto/.rvm/gems/ruby-2.7.4/gems/actionview-6.1.6/lib/action_view/rendering.rb:103:in `render_to_body'
     # /home/kireto/.rvm/gems/ruby-2.7.4/gems/actionpack-6.1.6/lib/action_controller/metal/rendering.rb:52:in `render_to_body'
     # /home/kireto/.rvm/gems/ruby-2.7.4/gems/actionpack-6.1.6/lib/action_controller/metal/renderers.rb:142:in `render_to_body'
     # /home/kireto/.rvm/gems/ruby-2.7.4/gems/actionpack-6.1.6/lib/abstract_controller/rendering.rb:47:in `render_to_string'
     # /home/kireto/.rvm/gems/ruby-2.7.4/gems/actionpack-6.1.6/lib/action_controller/metal/rendering.rb:41:in `render_to_string'
     # /home/kireto/.rvm/gems/ruby-2.7.4/gems/actionpack-6.1.6/lib/action_controller/renderer.rb:100:in `render'
     # /home/kireto/.rvm/gems/ruby-2.7.4/gems/actionpack-6.1.6/lib/action_controller/metal/rendering.rb:11:in `render'
     # ./lib/tasks/application.rake:171:in `block (2 levels) in <top (required)>'

I am wondering what it is that we are forgetting. Anyone has a clue?