You would make the change at your registrar, which may or may not be your hosting provider. If you don't know who your registrar is for the domain, you can find this by doing a WHOis search.
Still not finding what you need?
The Cloudflare team is here to help. 95% of questions can be answered using the search tool, but if you can’t find what you need, submit a support request.
Popular questions: Why is my site slow, 522 errors, I'm expecting a spike in traffic