DreamHost does support DS records, but you must first host your DNS with a third-party host that supports DNSSEC, like CloudFlare.
You will need 4 pieces of information to provide DreamHost with in order to get the DS record added, all of which can be found on the CloudFlare dashboard:
- key tag
- digest type
To find this data, you will want to activate DNSSEC for your zone on the CloudFlare dashboard.
Once you have this activated, you will get a pop up box that will display the information that you need to relay to DreamHost.
NOTE: Please Use 2 as the Digest Type, not SHA256
You will then create a support ticket to DreamHost to have the DS record added for your zone.
You can read the DreamHost Knowledge Base article here.