API for Encounter Observation forms

Situation
Hello. In encounter window I choosed Clinical->Observation. Created some test Observations. When I try to use API /api/patient/id/encounter/id - I get Encounter without any data from Observation forms. Also I tried to use API /fhir/Observation - there is also no any observations which I created in encounter. How I can get this observations from API?

OpenEMR Version
latest