Ard mediathek what to look at laptop mac pro?

I want to mediathek zb.nachrichten look ard or ndr and it does not work, then comes so egg a picture is not possible, but you Tube goes without problems

what do I have to do step by step thank you in advance

Try it: https://www.daserste.de/specials/service/faq-das-erste-mediathek-100.html

Many thanks priesterlein what actually not what cache is or how I have to do something with browser