GL-INET MT1300 (Beryl) WiFi interface not exist

[Pico]

looks like a general issue, you might need to stay on vendor firmware for a while, until OpenWRT development for that device has made more progress on WiFi:

MT1300 Wi-Fi problem

GL.iNet Beryl (GL MT1300) - Not working wifi built in

I have also got one today, I am using official OpenWrt firmware version 21.02.0-rc3 now, everything looks right except its Wi-Fi. If I enable both Wi-Fi devices, the whole system won't start after reboot, the only solution is recovering the system. Hope this serious problem can be fixed quickly in the future.