During making a custom template comment I see this notice:

Notice : Undefined index: comment_field in C:\xampp\htdocs\..\wp-content\themes\..\functions\comments-html.php on line 155

Following is my Code..Can anybody solve this?

Wordpress Version : 5.1.1 PHP 7.2

<?php function brick_comment($comment, $args, $depth) {
$GLOBALS['comment'] = $comment;
$comment_ID = get_comment_ID();
extract($args, EXTR_SKIP);
if ( 'div' == $args['style'] ) {
    $tag = 'div';
    $add_below = 'comment';
} else {
    $tag = 'li';
    $add_below = 'div-comment';
}
?>
<<?php echo $tag ?> <?php comment_class( empty( $args['has_children'] ) ? '' : 'parent' ) ?> id="comment-<?php comment_ID() ?>">
<div class="commentbox">
    <?php if ( 'div' != $args['style'] ) : ?>
    <div id="div-comment-<?php comment_ID() ?>" class="comment-body">
        <?php endif;
        $author_name = get_comment_author( $comment_ID );
        ?><div class="comment-inner-body">
            <div class="cm clearfix">
                <?php if ( $comment->comment_approved == '0' ) : ?>
                    <div class="comment-awaiting-moderation">
                        <?php _e( 'Your comment is awaiting moderation.' ); ?>
                    </div>
                <?php endif; ?>

                <div class="img">
                    <?php echo get_avatar( $comment, 80 ); ?>
                </div>
                <div class="txt">

                    <div class="headline clearfix">
                        <div class="right-head">
                            <span class="title"><?php echo $author_name; ?></span>
                            <span class="date"><?php echo get_comment_date('Y/m/d'); ?></span>
                        </div>
                        <div class="reply-comment left-header">
                            <?php comment_reply_link( array_merge( $args, array( 'add_below' => $add_below, 'reply_text ' => 'پاسخ به نظر', 'depth' => $depth, 'max_depth' => $args['max_depth'] ) ) ); ?>
                        </div>
                    </div>
                    <div class="details">
                        <?php comment_text(); ?>
                    </div>
                </div>
            </div>
            <?php if ( 'div' != $args['style'] ) : ?>
        </div>
    <?php endif; ?>
    </div>
</div>
<?php } if( ! function_exists('brick_comment_form') ){
/**
 * Comment form
 */
function brick_comment_form($args = array(), $post_id = null ){
    $post_id = get_the_ID();
    $commenter = wp_get_current_commenter();
    $user = wp_get_current_user();
    $user_identity = $user->exists() ? $user->display_name : '';
    if ( ! isset( $args['format'] ) )
        $args['format'] = current_theme_supports( 'html5', 'comment-form' ) ? 'html5' : 'xhtml';
    $req      = get_option( 'require_name_email' );
    $aria_req = ( $req ? " aria-required='true'" : '' );
    $html5    = 'html5' === $args['format'];
    $fields   =  array(
        'author' => '
        <div class="col-12 col-sm-12 col-md-4 pcol-5 padding-5">
            <div class="comment-form-author comment-field form-group">
                <input class="form-control" id="author" placeholder="نام و نام خانوادگی" name="author" type="text" 
                value="' . esc_attr( $commenter['comment_author'] ) . '" ' . $aria_req . ' />
            </div>
        ',
        'url'   => '
            <div class="comment-form-url comment-field form-group">' .
            '<input class="form-control" id="url" name="url" ' . ( $html5 ? 'type="url"' : 'type="text"' ) . ' value="' . esc_attr( $commenter['comment_author_url'] ) . '" maxlength="200" placeholder="نام سایت"/>
            </div>
    ',
        'email'  => '
            <div class="comment-form-email comment-field form-group">
                <input id="email" class="form-control" name="email" placeholder="آدرس ایمیل" ' . ( $html5 ? 'type="email"' : 'type="text"' ) . ' 
                value="' . esc_attr(  $commenter['comment_author_email'] ) . '" ' . $aria_req . ' />
            </div>
        </div>
    ',
        'comment_field'  => '
        <div class="col-12 col-sm-12 col-md-8 comment-text form-group clearfix  padding-5">
            <textarea class="form-control" id="comment" name="comment" placeholder="متن دیدگاه" aria-required="true"></textarea>
        ',
        'submit'  => '
            <label class="submitCM float-left ">
                <input class="btn send-btn" id="submit" name="submit" type="submit" value="ارسال" />        
            </label>
        </div>',
    );
    $required_text = sprintf( ' ' . __('Required fields are marked %s', 'websima'), '<span class="required">*</span>' );
    $defaults = array(
        'fields'               => apply_filters( 'comment_form_default_fields', $fields ),
        'must_log_in'          => '
<div class="alert alert-danger must-log-in">'
            . sprintf( __( 'You must be <a href="%s">logged in</a> to post a comment.' ), wp_login_url( apply_filters( 'the_permalink', get_permalink( $post_id ) ) ) )
            . '</div>',

        'logged_in_as'  => '<div class="col-12"><div class="alert-by-comment"><div class="alert logged-in-as">' . sprintf( __( ' شما با نام کاربری <a href="%1$s" class="trn_elm_all">%2$s</a> وارد شده اید . <a href="%3$s" title="Log out of this account" class="log-out trn_elm_all">خروج</a>', 'websima' ), get_edit_user_link(), $user_identity, wp_logout_url( apply_filters( 'the_permalink', get_permalink( $post_id ) ) ) ) . '</div></div></div>
<div class="col-12">
    <div class="form-group comment-form-comment">
        <div class="comment-text">
            <textarea class="form-control" id="comment" name="comment" placeholder="' . _x( 'اینجا پیام خود را بنویسید...',  'websima' ) . '" rows="5" aria-required="true"></textarea>
        </div>
        <div class="form-submit text-left when_login">
            <div class="send-for-damin">
                <input class="comment-sent full-btn btn send-btn"  id="submit" name="submit" type="submit" value="ارسال" /> 
            </div>
        </div>
    </div>
</div> ',

        'comment_notes_before' => '',
        'comment_notes_after'  => '<div class="form-allowed-tags">' . sprintf( __( 'You may use these <abbr title="HyperText Markup Language">HTML</abbr> tags and attributes: %s', 'websima' ), ' <code>' . allowed_tags() . '</code>' ) . '</div>',
        'id_form'              => 'commentform',
        'id_submit'            => 'submit',
        'title_reply'          => __( 'Leave a Reply', 'websima' ),
        'title_reply_to'       => __( 'Leave a Reply to %s', 'websima' ),
        'cancel_reply_link'    => __( 'انصراف', 'websima' ),
        'label_submit'         => __( 'Post Comment', 'websima' ),
        'format'               => 'xhtml',
    );
    $args = wp_parse_args( $args, apply_filters( 'comment_form_defaults', $defaults ) );
    if ( comments_open( $post_id ) ) { ?>
        <?php do_action( 'comment_form_before' ); ?>
        <div id="respond" class="comment-respond">
        <?php if ( get_option( 'comment_registration' ) && !is_user_logged_in() ) { ?>
            <?php echo $args['must_log_in']; ?>
            <?php do_action( 'comment_form_must_log_in_after' ); ?>
        <?php } else { ?>
            <form action="<?php echo site_url( '/wp-comments-post.php' ); ?>" method="post" id="<?php echo esc_attr( $args['id_form'] ); ?>"
                  class="row form-horizontal border_bt comment-form"<?php echo $html5 ? ' novalidate' : ''; ?>  >
                <?php do_action( 'comment_form_top' ); ?>
                <?php if ( is_user_logged_in() ) { ?>
                    <?php echo apply_filters( 'comment_form_logged_in', $args['logged_in_as'], $commenter, $user_identity ); ?>
                    <?php do_action( 'comment_form_logged_in_after', $commenter, $user_identity ); ?>
                <?php } else { ?>
                    <?php echo $args['comment_notes_before']; ?>
                    <?php
                    do_action( 'comment_form_before_fields' );
                    foreach ( (array) $args['fields'] as $name => $field ) {
                        echo apply_filters( "comment_form_field_{$name}", $field ) . "\n";
                    }
                    do_action( 'comment_form_after_fields' );
                }
                echo apply_filters( 'comment_form_field_comment', $args['comment_field'] );
                echo $args['comment_notes_after']; ?>
                <?php comment_id_fields( $post_id ); ?>
                <?php do_action( 'comment_form', $post_id ); ?>
            </form>
            </div>

        <?php } ?>

        <?php do_action( 'comment_form_after' ); ?>
    <?php } else { ?>
        <?php do_action( 'comment_form_comments_closed' ); ?>
    <?php } ?>
    <?php
} }?>

line error :

echo apply_filters( 'comment_form_field_comment', $args['comment_field'] );

thanks :)