How to pass some parameter to fosuserbundle in symfony

I am using fosuserbundle to manage users on my website. it works correctly, but I need to add "lang" parameter to fos routers to add multi-language support. now the problem is when trying to register it, this error is returned:

Some mandatory parameters are missing ("lang") to generate a URL for route "eartman_designer_registration_confirm".

      

        
        
        
      

    

my router:

  eartman_designer_security:
        resource: "@EartmanDesignerBundle/Resources/config/routing/security.yml"
        prefix: /designer/{lang}

    eartman_designer_profile:
        resource: "@EartmanDesignerBundle/Resources/config/routing/profile.yml"
        prefix: /designer/{lang}/profile

    eartman_designer_register:
        resource: "@EartmanDesignerBundle/Resources/config/routing/registration.yml"
        prefix: /designer/{lang}/register

    eartman_designer_resetting:
        resource: "@EartmanDesignerBundle/Resources/config/routing/resetting.yml"
        prefix: /designer/resetting

    eartman_designer_change_password:
        resource: "@EartmanDesignerBundle/Resources/config/routing/change_password.yml"
        prefix: /designer/{lang}/profile
    eartman_designer_design:
        resource: "@EartmanDesignerBundle/Resources/config/routing/designer_design.yml"
        prefix: /designer/{lang}/design

      

        
        
        
      

    

and the registration router:

eartman_designer_registration_register:
    path: /
    defaults: { _controller: "FOSUserBundle:Registration:register" }

eartman_designer_registration_check_email:
    path: /check-email
    defaults: { _controller: "FOSUserBundle:Registration:checkEmail" }
    methods: "GET"

eartman_designer_registration_confirm:
    path: /confirm/{token}
    defaults: { _controller: "FOSUserBundle:Registration:confirm"}
    methods: "GET"

eartman_designer_registration_confirmed:
    path: /confirmed
    defaults: { _controller: "FOSUserBundle:Registration:confirmed" }
    methods: "GET"

      

        
        
        
      

    

how can i pass lang parameter to register ?????