If there is a Route object in the ServerWebExchangeUtils.GATEWAY_ROUTE_ATTR exchange attribute, the RouteToRequestUrlFilter runs. It creates a new URI, based off of the request URI but updated with the URI attribute of the Route object. The new URI is placed in the ServerWebExchangeUtils.GATEWAY_REQUEST_URL_ATTR exchange attribute`.

If the URI has a scheme prefix, such as lb:ws://serviceid, the lb scheme is stripped from the URI and placed in the ServerWebExchangeUtils.GATEWAY_SCHEME_PREFIX_ATTR for use later in the filter chain.