Can not open Nuki Box via Web API

I’m trying to open Nuki Box via we Web API, but receive http status code 403 in response.
I use API key to send request to Web API and send request to /smartlock/{smartlockId}/action. All rights I selected when created new API Key.
Also I’m able to get list of locks with this key, but can not get info for Nuki Box directly. Web API returns 403 too.
Under this account registered only 1 Nuki Box and no other locks.
Any ideas how to fix it?

Hi Konstantin!

I just retested it here with me and had no problems sending a lockAction to a Box via Web API.
Could you send me your request and reply via PM so I can check the details?