Google Cloud Functions and Third Party Packages

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