Hi friend!
Wi-Fi cannot be disabled directly in the VAS profile. Therefore, we need to disable the SSID in the ONT, which will prevent access. Also, hide the SSID on the web GUI.
1. Add WLAN instance, which is the SSID.

2. Disable the SSID and disable the visibility on the Web page.

3. There can be 4 SSIDs configured in the ONT. Add all of the mas like above and disable all of them.

I hope I can help you!