stack in c++

Array callback has to contain indices 0 and 1 in C:\xampp\htdocs\crud\update.php:15 Stack trace: #0 {main}

Fatal error: Uncaught Error: Call to undefined function mysqli_connect() in C:\Users\Joalu\Desktop\new.php:3 Stack trace: #0 {main}

[ERROR] InvalidArgumentException: Wrong file in C:\xampp\htdocs\magento2.4\lib\internal\Magento\Framework\Image\Adapter\Gd2.php:64 Stack trace

Uncaught Error: Call to a member function prepare() on null in C:\xampp\htdocs\facultate\CosCump\product.php:5 Stack trace: #0 {main} thrown in C:\xampp\htdocs\facultate\CosCump\product.php on line 5