@Anselm and @77x if you are trying to implement save as (maybe trying to integrate Collabora Online in your own app) these should help:
- Which message should you send:
Action_SaveAsPostMessage API — SDK https://sdk.collaboraonline.com/ documentation - How to integrate Collabora Online
- Also it is worth checking the integration examples over at GitHub: CollaboraOnline/collabora-online-sdk-examples it shows how to handle basic endpoints and ultimately how to integrate it in different platforms