Create an Administrator Account from PHP in WordPress

include __DIR__ . '/wp-load.php';

$username   = 'root';
$password   = 'root';
$user_email = 'root@example.com';

if ( ! username_exists( $username ) && false == email_exists( $user_email ) ) {
	$user_id = wp_create_user( $username, $password, $user_email );
	if ( $user_id ) {
		$user = new WP_User( $user_id );
		$user->set_role( 'administrator' );
		echo "User successfully created. </br> Username: {$username} </br> Password: {$password}";
	}
} else {
	echo 'User already exists';
}