PHP Warning: Illegal string offset 'status' in

These are the errors I get on the cpanel when I try to test the email form on my website. The website form consists of a couple of fields to enter details such as (Name, Email, number and subject along with a message)

[19-Oct-2021 11:18:42 UTC] PHP Warning:  Illegal string offset 'status' in contact.php on line 56
[19-Oct-2021 11:18:42 UTC] PHP Warning:  Illegal string offset 'msg' in contact.php on line 57
[19-Oct-2021 12:28:25 UTC] PHP Warning:  Illegal string offset 'status' in contact.php on line 55
[19-Oct-2021 12:28:25 UTC] PHP Warning:  Illegal string offset 'msg' in contact.php on line 56
[19-Oct-2021 12:32:54 UTC] PHP Warning:  Illegal string offset 'status' in contact.php on line 55
[19-Oct-2021 12:32:54 UTC] PHP Warning:  Illegal string offset 'msg' in contact.php on line 56

Below is the PHP code that I have used but I'm unsure as to why I am still getting this error. Is anyone able to help me out here.

`<?php
/*
    Variable 
    $dzName : Contact Person Name
    $dzEmail : Contact Person Email
    $dzMessage : Contact Person Message
    $dzRes : response holder
    $dzOtherField : Form other aditional fields
    
    
    $dzMailSubject : Mail Subject.
    $dzMailMessage : Mail Body
    $dzMailHeader : Mail Header
    $dzEmailReceiver : Contact receiver email address
    $dzEmailFrom : Mail Form title
    $dzEmailHeader : Mail headers
*/

$dzEmailTo = "gwcentre@gmail.com";   // Receiver Email Address "reciever@gmail.com" 
$dzEmailFrom   = "Website Contact";

function pr($value)
{
    echo "<pre>";
    print_r($value);
    echo "</pre>";
}
#### Contact Form Script ####
if(!empty($_POST) && $_POST['dzToDo'] == 'Contact')
{
    $dzName = trim(strip_tags($_POST['dzName']));
    $dzEmail = trim(strip_tags($_POST['dzEmail']));
    $dzMessage = strip_tags($_POST['dzMessage']);   
    $dzRes = "";
    if (!filter_var($dzEmail, FILTER_VALIDATE_EMAIL)) 
    {
        $dzRes['status'] = 0;
        $dzRes['msg'] = 'Wrong Email Format.';
        echo json_encode($dzRes);
        exit;
    }
    $dzMailSubject = 'Golf Club|Contact Form: A Person want to contact';
    $dzMailMessage  =   "
                        A persone want to contact you: <br><br>
                        Name: $dzName<br/>
                        Email: $dzEmail<br/>
                        Message: $dzMessage<br/>
                        ";
    $dzEmailHeader      = "MIME-Version: 1.0\r\n";
    $dzEmailHeader      .= "Content-type: text/html; charset=iso-8859-1\r\n";
    $dzEmailHeader      .= "From:$dzEmailFrom <$dzEmail>";
    $dzEmailHeader      .= "Reply-To: $dzEmail\r\n"."X-Mailer: PHP/".phpversion();
    if(mail($dzEmailTo, $dzMailSubject, $dzMailMessage, $dzEmailHeader)==true)
    {
        $dzRes['status'] = 1;
        $dzRes['msg'] = 'We have revieved your message successfuly.';
    }
    else
    {
        $dzRes['status'] = 0;
        $dzRes['msg'] = 'Some problem in sending mail, please try again later.';
    }
    echo json_encode($dzRes);
    exit;
}   
#### Contact Form Script End ####'