I can not add cookies for WebSocket

Hello! I began to study Gatling.

Trying to write a simple script to connect to WebSocket. when I run the script, I get an error: [ERROR] i.g.h.a.c.AddCookieBuilder$$anon$1 - ‘addCookie-1’ failed to execute: Neither cookie domain nor baseUrl

Script:

package ru.tinkoff.load.myservice

import io.gatling.core.Predef._
import io.gatling.http.Predef._
import io.gatling.http.protocol.HttpProtocolBuilder

import scala.concurrent.duration._

class InformerWebSocketTest extends Simulation {

  val httpProtocol: HttpProtocolBuilder = http
    .wsBaseUrl("ws://my-websocket-baseurl")

  val scn = scenario("myWebSocketTest")
    .exec(addCookie(Cookie(name = "username", value = "testuser\\tqwyol")))
    .exec(ws("Connect WS").connect("/clientSocket/ws/"))
      .exec(ws("Close WS").close)

  setUp(
    scn.inject(atOnceUsers(1))
  ).protocols(httpProtocol)
}

Thanks for reporting: https://github.com/gatling/gatling/issues/3702