สอบถามค่ะเปิดเว็บมาแล้ว register ขึ้นแบบนี้ทันทีมีวิธีแก้ยังไงคะ

<?php
error_reporting(0);
include_once 'init.php';
 
$carer_user = $_POST["carer_user"];
$carer_pass = $_POST["carer_pass"];
$carer_fname = $_POST["carer_fname"];
$carer_lname = $_POST["carer_lname"];
$carer_birth = $_POST["carer_birth"];
 

 $fetch = mysqli_query($con,"SELECT carer_user 
 							 FROM `carer_info` 
 							 WHERE carer_user ='$carer_user'");



 $count = mysqli_num_rows($fetch);

    if($count!=""){
    	echo '{"This Username already exist"}';
    }else{
    	 $add = mysqli_query($con, "INSERT INTO carer_info (carer_user, carer_pass, carer_fname, carer_lname, carer_birth )
 		 							VALUES('$carer_user', '$carer_pass', '$carer_fname','$carer_lname', '$carer_birth' )");
    	echo '"Register successful."';

    }
 
?>

<?php
 
error_reporting(0);
 
$db_name = "u957762221_db";
$mysql_user = "u957762221_db";
$mysql_pass = "123456";
$server_name = "localhost";
 
$con = mysqli_connect($server_name, $mysql_user, $mysql_pass, $db_name);
 
if(!$con){
    echo '"Unable to connect to the database."';
}
 
?>