how to submit a form data to the controller which is within vendor directory

Question

I'am using yii2basic template where I am using himiklab search component to make a lucene search after doing the the installation through composer himiklab directory is created within vendor then there is a module which contain controller and corresponding view. I have created a search form in my layout like this

<?php ActiveForm::begin
([
    'action' => ['default/index'],
    'method' => 'post',

]);
?>

<input  type="text" name="name">
<input  type="submit" name="submit" value="Search">
<?php ActiveForm::end();?>

now i want to call the action in controller inside himiklab directory on the page submit which is default controller having action index. any help will be highly appreciated