Openwrt portal captive with sms otp

Dear all
I bought GL.iNet GL-MT3000 (Beryl AX) Pocket-Sized Wi-Fi 6 Wireless Travel Gigabit Router with pre-install openwrt and I’m using NETGEAR Nighthawk M6 Pro Mobile Hotspot 5G mmWave connected to GL.iNet via tethering.

I want to install portal captive support sms otp so no one can connect to GL.iNet wifi without put his mobile number to get otp code from sms
I hope it’s clear and I need your advice please
with regards

"kernel": "5.4.211",
        "hostname": "GL-MT3000",
        "system": "ARMv8 Processor rev 4",
        "model": "GL.iNet GL-MT3000",
        "board_name": "glinet,mt3000-snand",
        "release": {
                "distribution": "OpenWrt",
                "version": "21.02-SNAPSHOT",
                "revision": "r15812+885-46b6ee7ffc",
                "target": "mediatek/mt7981",
                "description": "OpenWrt 21.02-SNAPSHOT r15812+885-46b6ee7ffc"

I think the best option as far for documentation and also for a bit wider api.

Is OpenNDS, there is also opkg for OpenWrt :wink:

But finding a good sms otp provider that is a different thing, i have used duo before for maintaining ssh servers years ago and then moved to key authentication.

And then you have to implement the logic yourself via their api.