404 Not Found - nginx/1.26.1

@chanchal maiti Thanks for reaching here!

The error message you are seeing indicates that the web app is unable to connect to the MySQL database. The error message '404 Not Found - nginx/1.26.1' is a generic error message that is displayed by the NGINX web server when it is unable to find the requested resource.

To resolve this issue, you can try the following steps:

1. Could you confirm that the connection string for the MySQL database is correct and is configured correctly in the web app. You can check the connection string in the web app's configuration settings. Refer- https://video2.skills-academy.com/en-us/azure/app-service/configure-common?tabs=portal#configure-connection-strings
2. Check that the firewall rules for the MySQL database are configured correctly to allow traffic from the web app. You can check the firewall rules in the Azure portal.
3. See that the web app is configured to use the correct version of PHP and that the required PHP extensions for MySQL are installed. You can check the PHP version and extensions in the web app's configuration settings.
4. You may check the web app's logs for any error messages related to the MySQL connection. You can view the logs in the Azure portal.

let us know if issue remains