This is the Download ID required to enable automatic updates of JCH Optimize Pro. Please enter this ID in the Download Id textbox in Pro Options. Without this ID set, you will get an 'Package download failed' or 403 error when you try to update using Joomla's update extension. Otherwise you will have to update manually by logging into your account, download the plugin and install it using the Extension Manager.

Please note that this ID changes whenever you change or reset your password even if the new password is the same as the old one. If you do, you will have to re-enter the new ID in the plugin's settings to re-enable automatic updates.