@munirahyusof90 its very difficult to help you with your particular issue when you simply tag a “me too” comment onto an existing topic without providing any information about the type of hardware you are using, the code you are using, the steps you’ve been through and the subsequent messages that you’ve seen I the serial monitor, app and via LED flashes.
I’m going to close this topic, but I would suggest that you read this…
If you’re still having issues after reading that guide then I’d suggest you start a new “need help with my project” topic and provide ALL of the information that is requested when you create the topic, plus all of the information that I’ve stated above.
Pete.