Ok Thanks for your reply TD-er. Because of the hardware reboots, the SONOFF is useless anyway. Buying another one with the new firmware and sending it to the location may be the only way. So this is why I was asking for a way to try the OTA update anyway.

Hello there, How can we update the unit from Wifi? 'OTA not possible' and no load button available. My unit is 9000Km from home so I'm trying to find a way via wifi.

Thanks!