Sqm for Wireless Repeater (relayd bridge)

I just set up my openwrt router as a wireless repeater for my main router using relayd. Can anybody guide me in how to set up sqm on the router which is wireless repeater. I don’t want to mess up trying to use the guide provided by openwrt because this router is just a repeater.

So how will it do SQM if it doesn't route or process traffic?