<form method="post">
    <table class="">
        <?php
        wp_nonce_field(self::$exportNonceAction, self::$exportNonceField);
        ?>
        <tr>
            <td colspan="2">
                <div>
                    <input class="button button-primary" type="submit" value="Export" name="<?php echo self::$exportNonceAction; ?>" id="submit_button">
                </div>
            </td>
        </tr>
    </table>
</form>