AX 1800 WiFi Mesh Extender (EAX 15)

Hi I'm using AT&T Fiber for my Internet, TV, and Phone which includes my WiFi.  I have some weak areas in my wifi that I'm looking to correct.  I'm considering the AX 1800 WiFi Mesh Extender (EAX 15) possibly 2 of them.  As I'm doing my research in the manual is says: "If your router’s WiFi security is set to WPA enterprise, WPA2 enterprise, or WEP, your extender can’t connect to your router. You must change your router’s WiFi security setting."  I've checked my router's settings it is a BGW 320 and it is currently set to WPA2.  So I'm assuming that I have to change something or I can't use this product.  My concern is that if I change my setting on my Router (and I'm not sure what other settings I can change them to) will that impact the security of my network?  I'm not Tech Savvy enough to know the differences in these security settings.  If this product is not compatible with my Router is there another Netgear product I should consider?  Thank you