Custom page url

Hi there !
I'm trying to set a parameter in a custom page url (see attached), but I'm getting an error :

Missing required parameter for [Route: filament.pages.{$id}/feature] [URI: admin/{$id}/feature] [Missing parameter: $id].

Missing required parameter for [Route: filament.pages.{$id}/feature] [URI: admin/{$id}/feature] [Missing parameter: $id].

What am I missing ?

Custom page url - Filament