Select checkbox multiple by custom attribute and get value

I have a project to learn something. I have a booking system that books movies seats. It is all well done, but now I want to put a custom value on a checkbox and when it is checked I want to get the value from that attribute and I want to pass it into an ajax request. Here is my code:

<script>
$(document).ready(function (e){
    $("#frmRezerva").on('submit',(function(e){
        e.preventDefault();
         var $fields = $(this).find('input[name="scaun_film[]"]:checked');
         if (!$fields.length) {
            alert('Selectati un scaun sau mai multe!');
                return false; 
        }
        var arr=[];
             $.each($("input[name='scaun_film[]']:checked"), function(){            
                    arr.push($(this).val());
            });

             //console.log(arr)
        $("#mail-status3").hide();
        $('#rezBtn').hide();
        $('#loader-icon3').show();
        $.ajax({
            url: "rezervare.php",
            type: "POST",
            dataType:'json',
            data: {
            "arr": arr,
            "id_movie":$('input[name="id_movie"]').val(),
            "nume_film":$('input[name="nume_film"]').val(),
            "gen_film":$('input[name="nume_film"]').val(),
            "nota_film":$('input[name="nota_film"]').val(),
            "user_id":$('input[name="user_id"]').val(),
            "user_email":$('input[name="user_email"]').val(),
            "data_film":$('select[name="data_film"]').val(),
            "bilete_film":$('input[name="bilete_film"]').val(),
            "cinematograf":$('select[name="cinematograf"]').val()},             
            success: function(response){
                window.setTimeout(function(){location.reload()},2000)
            $("#mail-status3").show();
            $('#loader-icon3').hide();
            if(response.type == "error") {
                $('#rezBtn').show();
                $("#mail-status3").attr("class","alert alert-danger");               
            } else if(response.type == "message"){
                $('#rezBtn').show();
                $("#mail-status3").attr("class","alert alert-success");                          
            }
            $("#mail-status3").html(response.text);  
            },
            error: function(){} 
        });
    }));
});
</script>

Here is my jquery where i select if the checkbox was checked. I can get the value but I want the same thing but only from a custom attribute. My custom attribute is seatName with a value from the database. EDIT: html here is :

<?php 
                    $sqlsq = "SELECT * FROM scaune WHERE id_scaun_movie='{$_GET['id_movie']}'";
                    $resultsq = mysqli_query($conn, $sqlsq);
                    while($rs = mysqli_fetch_assoc($resultsq)){?>

<?php if($rs['ocupat'] == 1){?>
    <div class="box">
        <label>
            <input type="checkbox" value="<?=$rs['id'];?>" disabled checked><span class="label-text"></span>
        </label>
    </div>

    <?php }else{?>
        <div class="box">
            <label>
                <input type="checkbox" value="<?=$rs['id'];?>" seatName="<?=$rs['scaun'];?>" name="scaun_film[]"><span class="label-text"></span>
            </label>
        </div>
        <?php } ?>

            <?php } ?>

So what i need to do is to select chair name and id of that chair to update in mysql rezerved, but i dont find a solution to get id and name of chair when is checked also i need to be more than 1 so if is checked 3 chairs to get all name seats checked. Thanks!