I'm trying to get my website working publicly (my host is Namecheap), but I'm having some trouble with my sign-in-page. After I submit my log-in-form 500 Internal Server Error appears. I checked my error logs and found the following error:
PHP Fatal error: Uncaught Error: Call to undefined function mysqli_fetch_all()
My PHP version is 7.3 and I have mysqlnd on. Here is the line that raises the error:
$user_data = mysqli_fetch_all($query_result, MYSQLI_ASSOC)[0];
$query result is the value of this expression:
mysqli_query($conn, "SELECT * FROM `users` WHERE `email` = '$email';");
The website works flawlessly locally using XAMPP.