CNAME  or Canonical Name is an entry at DNS as record that used to be an alias and direct website or domain into specific address (as A record/not as an IP assress). TXT record is a record that is used to store text information on the hosting domain. Here is how to add a cname record:

• Create Bucket with a valid domain name.

• Then, adding read access at General Permission for a file which can be accessed via subdomain.

• Adding CNAME record with a bucket name which has the same subdomain name.

Try to access the Object Storage file with subdomain name that has been declared. Here is the result: