Press the POWER button of your Sauna for 5 seconds. This will start the WiFi Configuration Mode. This shows the WiFi strength in the TEMP area of the display and it shows the WiFi connection state status in the TIME area of the display. This will stay on for 2 minutes.
wifi_state=0: It cannot find WiFi mode
wifi_state=1: The WiFi could not connect to the router
wifi_state=2: The WiFi is connected to the router but could not connect to the iCloud server
wifi_state=3: The Wifi is connected to both router and to the iCloud server successfully and all should be working correctly
Please see the attached PDFs for further information on WiFi frequencies and app installation.