QSS/WPS button in TP-Link WR741ND

What I must do to re-enable WPS or QSS button to add new wireless devices?

Model

TP-Link TL-WR741N/ND v1

Architecture

Atheros AR7240 rev 2

Firmware Version

OpenWrt 18.06.2 r7676-cddd7b4c77 / LuCI openwrt-18.06 branch (git-19.020.41695-6f6641d)

P.S.: I am new in forum.