Cannot use CNAME , subdomain.

Hi,
My name is Semih, i am verry new at bitbucket.

I want to use :
http://bucket.semihmasat.info as a custom domain.
I create a CNAME "bucket" is an alias of bitbucket.org

But i get this error:

The hostname "semihmasat.info" does not resolve to bitbucket.org. Please check your DNS settings. (Your hostname currently points to
173.245.60.118.)

What should i do know ?

PS : i am using Cloudflare dns hosting and disabled cloudflare on it.