html - How to get Input or Select tag value inside a loop in PHP?

one text

Im working with my project it have table composed of text and select tag (dropdown).

I used php for loop to display data per row using <tr> tag.

Sample code of my tr tag

<?php
    $index = 0;
    while ($index < sizeof($json)) :
    ?>
            <tr>
                <?php ... ?>           
                    <td><?php echo $sample ?></td>
                    <td><?php echo $sample ?></td>
                    <td><?php echo $sample ?></td>             
                    <td>
                        <form id="myForm" action="include/test-inc.php" method="POST">
                            <div class="dropdown">
                                <select class="form-select" aria-label="Def ault select example" name="select[<?php echo $index; ?>]">
                                    <option selected value="false">False</option>
                                    <option value="true">True</option>
                                </select>
                            </div>
                        </form>
                    </td>
            </tr>
    <?php 
    $index++;
    endwhile;
    ?>
    <input type="submit" form="myForm" name="saveBtn" class="btn btn-primary w-25" value="SAVE">

Code for test-inc.php

if (isset($_POST['saveBtn'])) { 
     print_r($_POST['select']);

}

The test-inc.php return the output like this

Array ( [0] => false )

It only get the first item on a row in a table, not in a whole.

How I can get all those select tag value??