freshrss-kagi-summarizer/configure.phtml

<?php
  $api_key = FreshRSS_Context::$user_conf->kagi_api_key;
?>

<form action="<?php echo _url('extension', 'configure', 'e', urlencode($this->getName())); ?>" method="post">
  <input type="hidden" name="_csrf" value="<?php echo FreshRSS_Auth::csrfToken(); ?>" />
  <div class="form-group">
    <label class="group-name" for="api_key"><?php echo _t('ext.kagiSummarizer.configure.api_key'); ?></label>
    <div class="group-controls">
      <input type="text" name="api_key" id="api_key" value="<?php echo $api_key; ?>">
    </div>
  </div>
  <div class="form-group form-actions">
    <div class="group-controls">
      <button type="submit" class="btn btn-important"><?php echo _t('gen.action.submit'); ?></button>
    </div>
  </div>
</form>