How to set Sec-WebSocket-Protocol in Response Header

I am trying to develop a websocket server using Scala, Akka and Play Framework 2.7.
I am sending 2 different “Sec-WebSocket-Protocol” in the request. Say(“abc1.0”,“abc2.0”)

Consider the server accepts only the protocol “abc1.0”.
I want the server to process the request and return the response if the request header Sec-WebSocket-Protocol contains “abc1.0”. If not it should send a response with “Sec-WebSocket-Protocol” header as “abc1.0”.

How can I set the “Sec-WebSocket-Protocol” header in the response header?

Please check the code below and help us to solve this use case.

Server code:

 def chatServer(userId: String) = WebSocket.acceptOrResult[String, String] { request =>
  Future.successful {
    AuthenticationService.doBasicAuthentication(userId, request.headers) match {
      case Results.Ok =>
        Right(ActorFlow.actorRef { out =>
          ChatServiceActor.props(out, userId, ba.monitorActor, ba.cacheActor)
      case Results.Unauthorized =>
        Left(Unauthorized.withHeaders(("Sec-WebSocket-Protocol", "abc1.0")))

Client Request:

val (upgradeResponse, closed) =Http().singleWebSocketRequest(WebSocketRequest("ws://localhost:9000/chatServer/user1",
        extraHeaders = Seq(Authorization(BasicHttpCredentials(userId, "password@123")),SecWebSocketProtocol.create("abc1.0","abc2.0"))), flow)
	  val connected = { upgrade =>
      if (upgrade.response.status == StatusCodes.SwitchingProtocols) {
      } else {
        throw new RuntimeException(s"Connection failed: ${upgrade.response.status}")