# Integrations

| environment variable   | default | example                             | description                                                                                                                          |
|------------------------|---------|-------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------|
| `HD_PLANTUML_SERVER`   | -       | `https://www.plantuml.com/plantuml` | The PlantUML server that HedgeDoc uses to render PlantUML diagrams. If this is not configured, PlantUML diagrams won't be rendered.  |
| `HD_IMAGE_PROXY`       | -       | `https://image-proxy.example.com`   | **ToDo:** Add description                                                                                                            |