Multiple android device connection throught wifi local network

Question

I want to use 2 android devices, 1 as a server and 2 as a client. And this process should be through the local network, so the 1st device will have to open a hotspot and the 2nd device will have to connect to it. I did the same process but connect from 2 devices to the server It doesn't work. I don't understand what I should do in this case. I mean, which thread should I connect to?

val client = HttpClient(Android) {
    install(Logging)
}

object KtorClient {
    var ipAddress: String = ""
    var ipv4Address = ""

    fun getData() {
        GlobalScope.launch {
            val data = client.request("http://$ipAddress:8080/api/data")
            println("DATA:${data.call.body<String>()}")
        }
    }

    fun otherGetData() {
        GlobalScope.launch {
            val data = client.request("https://$ipv4Address:8080/api/data")
            println("DATA:${data.call.body<String>()}")
        }
    }
} 
fun getLocalIpAddress(): String {
    try {
        val interfaces = NetworkInterface.getNetworkInterfaces()
        while (interfaces.hasMoreElements()) {
            val networkInterface = interfaces.nextElement()
            val addresses = networkInterface.inetAddresses
            while (addresses.hasMoreElements()) {
                val address = addresses.nextElement()
                if (!address.isLoopbackAddress && address.hostAddress.contains(":").not()) {
                    return address.hostAddress ?: ""
                }
            }
        }
    } catch (e: Exception) {
        e.printStackTrace()
    }
    return "N/A"
}