website/config/routes.yaml

error:
  path: '/error/{status}'
  defaults:
    _controller: App\Controller\DefaultController::ErrorAction
    status: '404'

default:
  path: '/{slug}'
  defaults:
    _controller: App\Controller\DefaultController::DefaultAction
    slug: 'index'
  requirements:
    slug: "[a-zA-Z0-9\/]+"