I have a public static ip configured on my main router (Zyxel). I am using an ethernet cable to connect and use public static ip, as a wireless connection is not compatible with that router. Can I somehow use the static ip wirelessly, with the help of a secondary router (ZyXEL). If so, how do I configure it?
Sure. Just attach another router configured as an AP to your main router LAN to LAN.
The secondary router (AP) will have DHCP disabled and give that device an address that is in your main router network range (so if main router is 192.168.x.1 make the AP router 192.168.x.y where y is not 1 and is not in the DHCP range of the main router that assigns devices their dynamic address). So this AP router will have a static address within the main router /24 range.
So for example, if your main router is 192.168.0.1 and it uses 192.168.0.2 to .99 for its DHCP assignable range, make your secondary AP address 192.168.0.100 or above (up to .254).
And on your AP router use at least WPA2/AES security with a good password and turn off WPA (prevent Reaver side port attacks) and name the 2.4 and 5GHz SSID whatever you like.