Lovelace resource

Hi all.

I am start working with advanced dashboard configuration.
I have create a layout with yaml, but I not able to use template.
Working ONLY if I insert the template directly in editor

I try to write a yaml file and include it using “add resource”, or insert in the configuration.yaml the code:

lovelace:
   resources:
     - url: template_file.yaml

nothing to do, the dashboard appears always like this

Can you help me?

Regards,
Marco