XHR GET Requests IV

I don’t understand why when inputting any word I don’t get any result. I’ve done all apparently correct. I’m not liking this, as I’m only creating constants and functions but I don’t see all what’s happening behind nor the purpose. If you can share any resources I would appreciate it. I would first try to do it by my own but I’m tight with math right now, I can’t dedicate so much time to programming nowdays. Thank you in advance.