USD navigation rule capturing "tel:" url on an interactive service hub page

Hello everyone,

Installed the Unified Service Desk Interactive Service Hub example by using the PackageDeployer (version 3.2)

I'd like to trigger an action when the user clicks on the business phone icon of a contact. When using a regular CRMPage the action can be triggered by using a navigation rule (as described here: https://community.dynamics.com/crm/f/117/t/153062) but how do I need to define the same navigation rule for an ISH page?

What I've tried so far:

- Navigation rule Order:1, Url: tel:, Route Type: In Place, Destination: Tab, Action: None

- When clicking on the phone icon - no event is shown in the Debugger and an IE popup appears asking me if i want to allow this website to open a program on my computer.

Thank you