5s Navigation with run/walk intervals?

I'm new to the Fenix 5s and the navigation features. I just set up a trail run course and synced it to my watch - this is great since this is a new trail for me and having navigation alerts will be super helpful.

I'm trying to figure out how to set up run/walk alerts inside of the navigation app, but not finding it. My course is configured as a "Trail run" type, but since I'm selecting the course from the navigation menu I'm not getting the run/walk alert settings.

Is this not possible? Is there a workaround that will allow me to use both the run/walk interval alerts AND navigation at the same time?

Thanks!