I want to send some SQL queries from PHP in the simplest way but also safe [duplicate]

<?php
$route = $_POST["select-route"];
$currentStop = $_POST["current-bus-stop"];
date_default_timezone_set("Asia/Kolkata");
$currentTime = date("h:i A");

$host = "localhost";
$dbname = "findmybus-test";
$username = "root";
$password = "";
        
$conn = mysqli_connect(hostname: $host,
                       username: $username,
                       password: $password,
                       database: $dbname);
        
if (mysqli_connect_errno()) {
    die("Connection error: " . mysqli_connect_error());
}           
        
$sql = "INSERT INTO `findmybustest` (route, location, time)
        VALUES (?, ?, ?);";

$stmt = mysqli_stmt_init($conn);

if ( ! mysqli_stmt_prepare($stmt, $sql)) {
    die(mysqli_error($conn));
}

mysqli_stmt_bind_param($stmt, "sss",
                       $route,
                       $currentStop,
                       $currentTime);

mysqli_stmt_execute($stmt);

echo "Record saved.";
?>

But when I ran it, the screen turned white (probably because of one of my error catching if statements) but I cant see the errors. I am completely new to SQL queries so please tell me what is the syntax error.