I don't know. If you setup the API token and configured it according to that page I linked earlier it should work. You may need to ask on the Cloudflare community. Or possibly some other volunteer here will know.
Some people accidentially use the config statements for the api key and not the api token.
Check this thread they had the same error message for a different reason: Cloudflare API not getting authenticated by LetsEncrypt on Home Assistant - #4 by _az
Check any restrictions like IP restrictions you may have placed in Cloudflare.