1. Go to this page and download the library: Download salmanbe/deepl 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/ */
DEEPL_URL=https://api-free.deepl.com/v2/translate // https://api.deepl.com/v2/translate for pro
DEEPL_KEY=your_deepl_api_key // Get api key from www.deepl.com