Generates an upload URL for uploading a file as an attachment to a specified contact.
To learn how to use the generated upload URL in the response to upload an attachment file, see the Upload API.
This method may require higher-level permissions than the caller has, based on their identity and roles and permissions. In these cases, you can ensure the method is called with the required level of authorization by using one of the following:
This method doesn't return any custom errors, but may return standard errors. Learn more about standard Wix errors.