Problem with rest type routing

[NicolaPez]

i'm upgrade my FOSUserBundle to 2.4 from 2.1 while i'm upgrading my project to Symfony 3.4 from 2.8

With the same code that before, and this yml file:

# app/config/routing.yml
api_request_backend:
type: rest
prefix: /api
resource: "@AppBundle/Resources/config/default.yml"

# AppBundle/Resources/config/default.yml
api:
type: rest    # This resource will have RESTful routes
prefix:
resource: "@AppBundle\Controller\ApiController"
name_prefix: api_

I reveice this error:

Exception thrown when handling an exception
(Symfony\Component\Config\Exception\FileLoaderLoadException: The file
"/var/www/project/src/AppBundle/Resources/config/default.yml" does
not contain valid YAML in
/var/www/project/src/AppBundle/Resources/config/default.yml (which
is being imported from "/var/www/project/app/config/routing.yml").
Make sure there is a loader supporting the "rest" type.)

[NicolaPez]

wrong repository, sorry