Login to wifi from b535 on dlink 921/openwrt and share network via LAN on dlink/openwrt

I got two routers:
Huawei B535 as main modem/router in my home, it has better modem than second one. Only this is for plus...

Second one is Dlink 921 with openwrt installed.

I'd like to login to wifi from b535 on dlink 921, and share LAN and internet on openwrt/dlink 921. How can I get login on dlink 921/openwrt in wifi network from B535

Login to OpenWrt on D-Link-921, go to Wireless, hit Scan, connect to your WiFi, and it should work.