Add dependencies to build.gradle

   dependencies {
       implementation("io.ktor:ktor-client:$ktorVersion")
       implementation("io.ktor:ktor-client-core:$ktorVersion")
       implementation("io.ktor:ktor-client-logging:$ktorVersion")
       implementation("io.ktor:ktor-client-content-negotiation:$ktorVersion")

       implementation("io.ktor:ktor-client-okhttp:$ktorVersion")
       implementation("io.ktor:ktor-client-websockets:$ktorVersion")
       implementation("io.ktor:ktor-serialization-kotlinx-json:$ktorVersion")
   }

Create a Websocket client factory

object WebSocketClientFactory {

    fun build(): HttpClient =
        HttpClient(OkHttp) {
            install(WebSockets) {
                this.pingInterval = 5000
            }
        }

    const val TEST_URL = "****** url here *****"
}

Send data to Websocket

fun HttpClient.send(request: SocketRequest) = flow<Frame.Text> {
    wss(host = WebSocketClientFactory.TEST_URL, path = "/ws") {
        println("Send ${request.method}")

        Json.encodeToString(request)
            .let(Frame::Text)
            .let {
                send(it)
            }

        while (true) {
            if (!isActive) break
            try {
                val othersMessage = incoming.receive() as? Frame.Text
                othersMessage?.let {
                    emit(it)
                }
            } catch (e: Exception) {
                println("WebSocket exception: ${e.localizedMessage}")
            }
        }

    }
}.cancellable()

In that case, the request data is in Json format

@Serializable
class SocketRequest {
        val method: Method,
        val params: Array<String>,
        val id: Int
}

enum class Method {
    SUBSCRIBE,
    UNSUBSCRIBE
}

Run the socket connection:

  val socketClient: HttpClient = WebSocketClientFactory.build()
  
  val request = SocketRequest(.....)
  
socketClient.send(reqquest)
   .flowOn(Dispatchers.IO)
   .collectLatest { .....  }

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