How do I execute this javascript along side html and css?

I'm currently using this domain as my url. https://morsetovoynich.000webhostapp.com/ This should be a simple procedure as I would like to use the anagram javacript code at my site. How do I implement the javascript code with html and css so I have a functional url? I can log in and ftp to my url so that's not an issue. When I upload and its done all I see is a blank screen.

 var generateAnagrams = (function() {
 // precomputed first 20 factorials
 var fact20 = [1, 2, 6, 24, 120, 720, 5040, 40320, 362880, 3628800, 39916800, 479001600, 6227020800, 
 87178291200, 1307674368000, 20922789888000, 355687428096000, 6402373705728000, 121645100408832000, 
 2432902008176640000];
 // Substrings seen already which we can cache. Try and avoid stack overflow as much as possible
 var seenStrings = {};

 function generateAnagrams(word) {
    var length = word.length;
    if (length < 2) {
        seenStrings[word] = word;
        return [word];
    }
    var anagrams = Array(fact20[length - 1]);

    // Stuff we'll need along the way
    var before, focus, after;
    var shortWord, subAnagrams, newEntry;
    var idx = 0, j, jlen;

    for (var i = 0; i < length; i++) {
        before = word.slice(0, i);
        focus = word[i];
        after = word.slice(i + 1, word.length + 1);
        shortWord = before + after;
        subAnagrams = seenStrings[shortWord] || generateAnagrams(shortWord);
        for (j = 0, jlen = subAnagrams.length; j < jlen; j++) {
            newEntry = focus + subAnagrams[j];
            anagrams[idx++] = newEntry;
        }
    }
    seenStrings[word] = anagrams;
    return anagrams;
 }

 return function anagrams(word) {
    var computed = generateAnagrams(word);
    // clear cache (going to consume a ton of memory)
    seenStrings = {};
    return computed;
 };
 })();