Hey @maria g12​ Racheal from the support engineer team here👋 

It looks like you've already worked this through with my teammate but for future viewers, it's not currently possible to change the format of the URL's to anything else. Reason being we have basic functionality around uploads/attachments so the ability to customize URLs would be restricted. We've logged this as a feature request for the team to consider.

In the meantime, a possible workaround and the team suggested was creating a custom domain using a reverse proxy with nginx/Apache, this would allow you to add a custom route to serve your custom files on the help center.