Is there an option to put a wireless access point to zyxel keenetic 4G II?

Question

network hardware

well, or something similar (except for the repeater)

There are 2 routers
Main asus
Secondary zyxel It is

necessary to expand the wireless network (new ssid, duplicating) over the air.

Asus-> over the air distributes the Internet -> zyxel-> distributes the Internet over the air to clients

Answer 1

Yes, this is possible.
Gullite: zyxel keenetic WDS setup