I need help for my project

why the (void loop ()) can not run if SSID or PASSWORD was incorrect
the program just stock and nothing runs from void loop
how can i run my code of void loop() if the SSID and PASS was correct or incorrect

Blynk.begin is a blocking function. If it cant connect to WiFi or the Blynk server then the code execution will stop at that point.
The solution is to manage the WiFi connection yourself, then use Blynk.config to specify the auth code and optional server IP and port, then use Blynk.connect to establish the connection to the server.

There are plenty of more details explanations and examples of how to use Blynk.config if you search this forum.

Pete.

thank you for the answer and your information