Checking if the parameter was correctly passed in View in ASP.NET Core Web Application

I have a problem with my Web Application. I managed to search through the jokes and display the ones that contain certain word (by using API https://icanhazdadjoke.com/), but I don't know how to display them in better way than this:

I have my async Task method that search jokes:

    [HttpPost]
    public async Task<List<string>> SearchJoke()
    {
        string searchedWord = Request.Form["word"];
        var client = _httpClientFactory.CreateClient("API Client");
        string url = client.BaseAddress + "search?term=" + searchedWord;
        string responseBody = await client.GetStringAsync(url);

        JokesModel jokes = JsonConvert.DeserializeObject<JokesModel>(responseBody);
        List<string> list = new List<string>();

        for (int i = 0; i < jokes.Results.Count; i++)
        {
            list.Add(jokes.Results[i].Joke);
        }

        return list;           
    }

And I just return a View like this:

    public IActionResult Index()
    {
        return View();
    }

My plan is to write something like this:

    public IActionResult Index()
    {
        //check if the word was passed and redirect to the another View which displays jokes
        // else show some message that the word is incorrect or there are no jokes contain that word

    }

I tried checking if the word was passed and wrote another method:

    [HttpPost]
    public bool GetWord()
    {
        string searchedTerm = Request.Form["word"];
        if (searchedTerm != null)
            return true;
        return false;
    }

And do something like this:

     public IActionResult Index()
    {
        if (GetWord())
        {
            return RedirectToAction(nameof(HomeController.SearchJoke), "Home");
            //this is the page where I display joke in more readable way
        }
        return View();
    }

But I got an error: "System.InvalidOperationException: „Incorrect Content-Type:" when I want to download word in GetWord() method.

Anybody can give me some advice or help me with this problem?