HTTP API and Cross origin request

I’m trying to write an AJAX call in javascript using the documentation here https://indico.readthedocs.io/en/latest/http_api/access/

My javascript is on a page hosted on a different server to where we host Indico.

I’m getting a cross-origin error.

Is there any way round this? Or must I write server-side code to use the API?

You can configure your webserver to send a Access-Control-Allow-Origin: * header for URLs starting with /export/ to allow CORS.

I thought that might be the answer. Unfortunately I don’t have access to the server config at the moment so was hoping there was another way.