get https://fhir-api.zapehr.com/r4b/Subscription//_history/
Subscription on the FHIR specification website.
The subscription resource is used to define a push-based subscription from a server to another system. Once a subscription is registered with the server, the server checks every resource that is created or updated, and if the resource matches the given criteria, it sends a message on the defined "channel" so that another system can take an appropriate action.