Issue in connecting my laptop to LAN/WAN port of Beryl AX

I just purchase Beryl AX router. I connected my router to existing wifi and want to use that connection through LAN/WAN port of Beryl AX router.
But Beryl AX router is not showing any LAN client
Please help and guide how can I use internet through LAN/WAN port of router.

I think you are refering to change WAN to LAN