i want when user select Country next dropdown show city that exist in countery

Hello,
Thanks for using WP Crowdfunding plugin. You can customize Submit Form- /wp-content/plugins/wp-crowdfunding/shortcode/submit-form.php Line#332-350

    //Country
    $html .= '<div class="wpneo-single">';
    $html .= '<div class="wpneo-name">'.__( "Country" , "wp-crowdfunding" ).'</div>';
    $html .= '<div class="wpneo-fields">';
    $countries_obj   = new WC_Countries();
    $countries   = $countries_obj->__get('countries');
    array_unshift($countries, __('Select a country', 'wp-crowdfunding') );
    $html .= '<select name="wpneo-form-country">';
    foreach ($countries as $key=>$value) {
        if( $country==$key ){
            $html .= '<option selected="selected" value="'.$key.'">'.$value.'</option>';
        }else{
            $html .= '<option value="'.$key.'">'.$value.'</option>';
        }
    }
    $html .= '</select>';
    $html .= '<small>'.__("Select your country","wp-crowdfunding").'</small>';
    $html .= '</div>';
    $html .= '</div>';

I have seen you are using ThemeForest premium theme. You can ask the support on the theme support forum.