Hello Richard,
For troubleshooting purposes, could you, please, clarify what control (e.g. checkbox) is used to specify the param-notificationtype parameter value and what values can be specified there? If it is a drop-down, post here or send us (support[at]softerra.com) a screenshot of the parameter configuration. We need something like the following:

Also, please, confirm that you check the notification in the same channel that is specified for the $uri variable.