melcloud mac-557if-e

I have old, now unsupported RT-AC66U unit with WPS function, running the last v380.70 firmware. I have few Mitsubishi Electric MAC-557IF-E IoT access devices, supporting only WPS-PUSH and WPS-PIN connection methods on b/g/n 2.4Ghz 13 channels, WPA2-AES. I have used WPS-PUSH method to pair these...