How to link to related pod in php template?

I’m struggling to get a working link to a related pod. Some more explanation:
Pod 1 -> agenda fietsroutes
Pod 2 -> fietsroutes
I have a php template to show upcomming fietsroutes from Pod 1(all routes for current week) and some additional info for that route from Pod 2. This all works fine. I want the name of the route in the agenda to be a link to the single related route so visitors can read additional information about that route.
I did find plenty of information on how to do this in a pods template, but not in a php template. Is there a field I can call directly (‘slug’ doesn’t work) or do I have to construct that link from different components?

Thanks in advance,
Bert.