Prototype Embed API does not fires events without figma session

Hello,

I'm trying to embed a figma-prototype into our application where I need to use the Embed API to track the movement of respondents through the prototype.
I need to read PRESENTED_NODE_CHANGED and INITIAL_LOAD.
I need to set last visited node after LOAD.

I'm having trouble getting the Embed API to work for unlogged users (no figma session, no figma cookie).

Your example on the website do that. And according to the documentation it should be possible.

https://developers.figma.com/docs/embeds/embed-api/#example-index-file

Prototype URL
https://embed.figma.com/proto/W6MiVVVuvJb5sdOihk2uxE/Unilever---Snack-snap?content-scaling=fixed&kind=proto&node-id=48-4510&page-id=1%3A2&scaling=scale-down&starting-point-node-id=48%3A4510&embed-host=cawi&client-id=Ptr4uxHDgFfqLl6vjtttEP

Prototype is shared public.
 

Demo 

https://cawi.nms.cz/3e1f3e8?

Expected Embed API works like this without be logged into figma.

When I am logged in:

But in anonymous window (without logged into figma) there are no events.

Prototype is loaded, but Embed API does not work, unless I am logged in Figma.

Thank you,
Any advice is welcome