1. Go to this page and download the library: Download yiibr/yii2-correios library. Choose the download type require.
2. Extract the ZIP file and open the index.php.
3. Add this code to the index.php.
<?php
require_once('vendor/autoload.php');
/* Start to develop here. Best regards https://php-download.com/ */
yiibr / yii2-correios example snippets
public function actions()
{
return [
...
'addressSearch' => 'yiibr\correios\CepAction'
...
];
}