Answers 
private fun getADvertise(onResult: (ArrayList<String>) -> Unit = {}) {
    CoroutineScope(Dispatchers.IO).launch {
        //Do Request To get Data using retrofit
        val result = ArrayList<String>()//result from retrofit
        withContext(Dispatchers.Main)
        {
            onResult(result)
        }

    }
}
private fun isProfileExist(): Boolean {
    //true or false
    return true
}

private fun getProfilePicture(id: String, OnResult: (String) -> Unit = {}) {
    CoroutineScope(Dispatchers.IO).launch {
        //Do Request To get Data using retrofit
        val result = "Link"//result from retrofit
        withContext(Dispatchers.Main)
        {
            OnResult(result)
        }

    }
}

//---------your main function------------------>
public fun execute(onResultMain: (ArrayList<String>) -> Unit = {}) {
    val exist = isProfileExist()
    if (exist) {
        getADvertise(onResultMain)
    } else {
        getProfilePicture("id") {

            getADvertise(onResultMain)
        }
    }

}
//onResultMain -> call back used to get result when they are ready ;)