How do I redirect the webpage in the code below?

[RealImmortal2004]

I’ve tried using the code below but I’m stuck as to what I need to add to make it redirect.

This is what I’ve got so far:

<?php
    
if ($_SERVER['REQUEST_METHOD'] == 'POST') {
                
    function get_data() {
        $name = $_POST['name'];
        $file_name='login-data'. '.json';

        if(file_exists("$file_name")) {
            $current_data=file_get_contents("$file_name");
            $array_data=json_decode($current_data, true);
                            
            $extra=array(
                'Username' => $_POST['Username'],
                'Password' => $_POST['Password'],
                'LoginDate' => $_POST['LoginDate'],
                'LoginTime' => $_POST['LoginTime'],
            );
            $array_data[]=$extra;
            echo "";
            return json_encode($array_data);
        }
        else {
            $datae=array();
            $datae[]=array(
                'Username' => $_POST['Username'],
                'Password' => $_POST['Password'],
                'LoginDate' => $_POST['LoginDate'],
                        'LoginTime' => $_POST['LoginTime'],
            );
            return json_encode($datae);
        }
    }

    $file_name='login-data'. '.json';
    
    if(file_put_contents("$file_name", get_data())) {
        echo '';
    }               
    else {
        echo '';               
    }
}   
?>