API - addwebhook

Hi,

Trying to add webhook. 

Here is the CLI command I am using:

curl -X POST "https://api.netatmo.com/api/addwebhook?url=https%3A%2F%2Fxsage.duckdns.org" -H "accept: application/json" -H "Authorization: Bearer XYZ"

Getting an error:

{"error":{"code":21,"message":"Invalid url parameter"}}%

Any suggestions what's wrong?