My blink project is using 3 esp8266 board and it is working perfectly thanks to blynk. Accidentally 1 board authentication code has been changed in the the app side hence that board connected bulbs are not working. remain boards are functioning properly. I have previous authentication code which I uploaded to hardware please advise how to modify the authentication code in the App side
As @Blynk_Coeur said, there is no relationship between your Blynk IoT account credentials and the credentials you use to log-in to this forum.
In the same way, if you’ve ever used Blynk Legacy then there is no relationship between Blynk Legacy login credentials and Blynk IoT login credentials and the Legacy and IoT Auth tokens are not interchangeable.
Okay, this is Blynk Legacy, which is no longer being developed or supported.
If you press the Refresh button in the app to generate a new Auth token for your device then it is not possible to specify the Auth token that is assigned to that device. The Auth tokens are randomly generated by the Blynk cloud server.
Your only option in this scenario is to re-flash your device with an updated sketch which uses the newly generated Auth token for that device.