After spending a few minutes playing it, I came out with the feedback below:
It would be nice if you added some sound effects for "hits" and "misses".
For better dynamics, consider varying the words length. It appears to me that you are serving only words with five letters.
It appears that you are having a bug that prevents the game from running smoothly on the following browsers: Firefox (Windows) and Brave (Windows/Android). I tried other browsers/OSes and the game was running perfectly: Chrome/Edge (Windows), Safari (iOS) and Firefox (Android). Apparently, the script at "https://cloud.umami.is/script.js" is not being loaded which causes an exception to happen when you lose; this prevents the game to show "Try Again" and the screen goes blank instead where you have to refresh the page to play again.
About word length: the difficulty of finding anagrams increases exponentially (a bit loosely used, but probably correct) with word length. But the game does increase length after a few steps, I just found out. A help page would perhaps be better.
And about adding sound effects: only if they can be turned off easily.
The game doesn't find anagrams though? What I saw was nonwords (random permutations of the letters).
Or if you mean the player's task, that's not finding anagrams either: you just need to choose the nonword that has the same counts of the letters as the word.
After spending a few minutes playing it, I came out with the feedback below: