Is the CORS error occurring in Webflow or on the server hosting the custom code?

The CORS error, which stands for Cross-Origin Resource Sharing, can occur in different scenarios depending on where the request is being made from and where it is being sent to.

In the context of Webflow, if you're attempting to make a request from custom code (such as JavaScript) within your Webflow project to an external server or domain, the error is likely occurring on the server that is hosting the custom code. This happens because by default, web browsers restrict cross-origin requests for security reasons. The server needs to explicitly allow the request to be made from a different origin.

To fix this error, you'll need to configure the server hosting the custom code to include the appropriate CORS headers in its response. These headers indicate which domains are allowed to make requests to the server. You can specify a wildcard (*) to allow requests from any domain, but this should only be done if you fully understand the security implications.

If, on the other hand, you're encountering the CORS error when embedding external content into your Webflow project, such as an API or an iframe, the issue is likely on the server hosting that external content. In this case, you'll need to reach out to the provider of the external content and ask them to configure their server to allow cross-origin requests from your Webflow project's domain.

It's important to note that the CORS error is a browser-enforced security restriction, so it can't be directly fixed within the Webflow designer interface or the Webflow hosting servers. You'll need to address it at the server level where the custom code or external content is hosted.