Is ZAK token mandatory when starting and joining events?

Description
Hello there, I was wandering if you can help me. I have two apps on zoom marketplace, first one is S2S OAuth app and second is Meeting SDK app. I use Meeting SDK app credentials to generate the signature and join the Webinars and Meetings that I make via Zoom API and S2S app. I saw in your documentation that ZAK token is needed, but I don’t use it and I am still able to start and join meetings and webinars. My question is: Is having and providing ZAK token mandatory when starting and joining events? I don’t think so, because as I said I AM able to start and join webinars and meetings, but I am wandering if it is a good approach?