The ability to import and export content types via API is available in our SaaS product, but not in the brXM on-prem / PaaS product. The expected mechanism for updating content types in brXM is via the deployment and bootstrapping mechanisms that require a process restart. More details are documented below. We tend to refer to this by the term “namespace”, since content types are typically organized into CND files that include multiple types organized by a common name prefix.
Note that you can still update content types without site downtime, but this requires more than one cluster node for hosting. There are also some updates that are best to handle in blue-green style deployments, if they require significant rewriting of existing content.