Hello @David_King
We will be happy to assist you. I need to ask you a few more questions so I can understand the problem better.
Here is our documentation - Backendless For Developers
Here is our documentation for the REST API - Backendless REST API Documentation
Please provide a link to the documentation you are referring to.
What packages are we talking about?
It is very difficult to answer such a question without knowing the complexity of these functions.
Maybe the solution described here - CORS issue with sendgrid - will help you.
Another topics - Cors and weird link for user services, Cors error
Regards,
Volodymyr