WiFi range extender with Hawaii Telcom Zyxel thing

[terracore]

I have some areas where the wifi is spotty and I was curious about using a range extender. Hopefully something simple and inexpensive. I have the Hawaii Telcom Zyxel fiber router thing. If you have any information to share please I want to read it. Here is one I've looked at, but I really don't know that much about them.

https://www.amazon.com/TP-Link-Extender-External-Antennas-TL-WA855RE/dp/B0195Y0A42/ref=as_li_ss_tl?smid=ATVPDKIKX0DER&linkCode=ll1&tag=pw016-20&linkId=9ca2481e72d4dd83d9fc6b81eb618508&language=en_US