To avoid authenticating each time you open a document containing an IQY file, you can use our API Account feature.
This application will let you create a key (GUID) that will be linked to a site and a list of API URLs. Using this key will allow you to bypass manual identification when using our REST API.
Once you have created your key, edit your IQY file to add it at the end of the URL: &apikey=MyAPIKey
You can now start using your Excel file without the need for authentication.