ShortPixel is a well-used plugin for image optimization on sites. The plugin includes a number of filters and constants. You can hide your ShortPixel API key from the plugin’s settings by defining the API key in a constant in the sites wp-config.php file. Replace out the APIKEY with your actual API key for ShortPixel. define(‘SHORTPIXEL_API_KEY’, ‘APIKEY’); define(‘SHORTPIXEL_HIDE_API_KEY’, true); If you are using the ShortPixel plugin and service on sites which are hosted on FlyWheel then you might run into an error saying that flock (file locking) has been disabled for security reasons by using this constant in your sites wp-config.php