Why redirect not working?

I ma using this jar “spring-boot-starter-oauth2-client” and redirect not working

class LoggingGlobalFilter: GlobalFilter {
override fun filter(exchange: ServerWebExchange, chain: GatewayFilterChain): Mono {
var uri = URI.create(“http://localhost:8080/logout”)

    val modifiedRequest = exchange
        .request
        .mutate()
        .uri(uri)
        .build();

    val modifiedExchange = exchange
        .mutate()
        .request(modifiedRequest)
        .build()
    modifiedExchange.attributes[ServerWebExchangeUtils.GATEWAY_REQUEST_URL_ATTR] = uri
    
    return chain.filter(modifiedExchange)
}

}