How can i send the Calendar feed to Apple Calendar

Up till now we have been using the Apple Calendar so we see it across all our devices.

In Ninox i have the Calendar working see screen shot,

But i do not see other Calendar features we use.

It dose not auto show normal holidays.

And i do not see a way to just add in some basic items like birthdays and doc appointments and so on with out creating a new customer record?

I read that somehow i should be able to send all the Ninox info into the Apple Calendar that would fix all this. I think this would work best for us

How i can set it up so all Ninox checked items get also sent to my Apple Calendar so we keep all our birthdays and other appointments all in one place..

Ninox support sent me this image showing to click on this icon to get a pop up window to make it go to the apple Calendar but in my DB this will not click on nothing happens i get no pop up window or anythign when i click on that.
 

Here is mine it is non clickable even in edit mode?.