Note: The REST API connector is being deprecated. A better alternative, with similar functionality and additional settings, is the universal HTTP connector.
While the REST API connector still appears in the + Create Connection pane, it now automatically defaults to the HTTP connector.
Existing REST connections are still available and are not affected by the change. However, you can't create new flow steps (connection, import, export, etc.) using a REST endpoint. Despite this, generating a new HTTP flow step for an existing REST flow won't count against your endpoint capacity as long as the base URIs are the same. You can create HTTP flow steps for existing REST flows with no penalties to your endpoint capacity.