Comment form not supported the image tags

Hi please use below code in your functions.php to allow img tag in comments. For details please follow link wp_kses_allowed_html and for more details please follow trac link

add_filter( 'wp_kses_allowed_html', array( $this, 'my_kses_allowed_html_hook' ), 20, 2 );

function my_kses_allowed_html_hook( $tags, $context = null ){
    if ( 'post' == $context && ! isset( $tags['img'] ) ) {
        $tags['img'] = array(
            'src' => 1,
            'height' => 1,
            'width' => 1,
            'alt' => 1,
            'title' => 1
        );
    }

    return $tags;
}

Thanks!