This could be solved in different ways depending on what the issue is.
First, if you have the same phone but both the phone and the MCU have changed the WiFi network you were connected to you need to connect the USB to the laptop, open 115200 baud rate and type “setup <ssid> <password>. This is detailed in the user guide.
If you are changing your phone for another one you need to do a factory reset. Hold SW1 for more than 10 seconds. If you have any further questions about the factory reset, use the user guide
Best Regards,
Fabian
