It is required to copy the API key immediately after it has been generated. Since we don't store API-Keys with authentic namings for the sake of security issues. If you did not copy it from the generation window, we recommend you delete it, generate a new one again, and copy it with the original naming.
You must upload this file to the root directory of your site where the root files are located (usually in the directory with index.php)
Check the version of your PHP, at the moment, versions below 7.0 are not supported by our agent manager, however, we plan to do this.
If you have an old version of PHP, we recommend that you upgrade for your safety.
Check permissions on your site and user rights.
Permit to edit the downloaded file to the user who runs PHP. To find out which user php is running from, you need to find the PHP configuration file, for example, in /etc/php/fpm/pool.d/www.conf It has a www section and user and group values.
Make sure that you correctly added the site to your account (check the HTTP or HTTPS protocol).