Service add weight route 404,what is the right way to add weight?

the service name is 'myservice' when not add weight the route is ok
but after add weight to this service, the route for this service is 404 , why?
what is the right way to add weight?

traefik/http/services/myservice/weighted/services/0/name myservice
traefik/http/services/myservice/weighted/services/0/weight