Variables/Tokens/Placeholders in Notification URL

[sneak-it]

Hi all, having an issue utilizing variables/tokens/placeholders in the notification URL. Utilizing Home Assistant to pass notifications, and my goal is to set the nid to the unique ID of the watch, so I can maintain separate notifications per watch. Here is my current URL which works:

hassio://<ip>/longaccesstoken?verify=no&nid=changedetection

Here's what I'm trying to use:

hassio://<ip>/longaccesstoken?verify=no&nid={{watch_uuid}}

But I'm greeted with
hassio://<ip>/longaccesstoken?verify=no&nid={{watch_uuid}} is not a valid AppRise URL.

According to a few lines below we can utilize tokens ({{watch_uuid}} being one of them), but it doesn't seem to be working as expected? Any help would be appreciated!