Warning: Undefined variable $ADMIN in C:\Apache24\htdocs\moodle\admin\settings\payment.php on line 25

Fatal error: Uncaught Error: Call to a member function add() on null in C:\Apache24\htdocs\moodle\admin\settings\payment.php:25 Stack trace: #0 {main} thrown in C:\Apache24\htdocs\moodle\admin\settings\payment.php on line 25