REST API with attachments

[rcapcap]

First off, thank you Fabric team for this very awesome tool!
I am calling Fabric through REST API's /chat endpoint. I am able to pass along the User Input, Pattern, Model and even Context in JSON. But if I add the Attachment parameter i.e. "attachments": "https://example.com/image.png" it does not seem to recognize it. If I run it via CLI it can recognize the image file even via a URL. I even tried using a local file i.e. "attachments": "image.png" but no luck.