Hello there and welcome to Just Answer. My name is ***** ***** I will be assisting you today. I am an engineer with over 30 years of electrical and electronic training, repair and installation experience. I will try and answer your question accurately and precisely so that we can get you on your way.
An authentication problem means that the password ***** are using to connect to WiFi is incorrect. So...are you sure you have the correct password? It would possibly be written on a label on the actual router.