"call to undefined function imagecreatetruecolor" error in PHP & pChart

The "call to undefined function imagecreatetruecolor" error in PHP typically occurs when the GD library, which is required to create image resources, is not installed or enabled on the server. To fix this error, you can try installing the GD library or enabling it in the PHP configuration file (php.ini) by uncommenting the extension=php_gd2.dll line or install gd library using package manager.

In addition, make sure that the pChart library is properly installed and configured. Check that the correct path to the library is being used in your code and that the necessary dependencies are installed and enabled.