Allow Calaméo to access your resources
For security reasons, Calaméo cannot access files on other websites. In order to load your CSML file and your skin elements, you have to grant Calaméo access to it.
The Access-Control-Allow-Origin header
You need to enable CORS (Cross-Origin Resource Sharing) for your custom skin XML and graphic resources files.
For more information on how to enable CORS, simply follow the steps detailed here: https://enable-cors.org/