Stop registration if customer_code field does not equal ABCDE

Note: You can add the code snippet to your theme’s functions.php file or use the Code Snippets plugin.

NOTE: We have created this code example to provide guidance and to make it easier for you to implement this code into your website. However, we are not able to provide any support when it comes to customizing the plugin. If you need help implementing this code, please hire a developer.