adding google calender

Is there a way to insert a "Add to Google/Outlook Calendar" to an event registration form template?

We do not have such integrations directly from the JotForm form builder, but you could send your submissions to Google Calendar using Zapier, which already provides an integration between JotForm and Google Calendar. 

Here's the link: https://zapier.com/zapbook/zaps/2606/create-google-calendar-event-from-new-jotform-submission/ 

You could also create a calendar report from your submissions, here's a guide about it: https://www.jotform.com/help/249-How-to-Create-a-Calendar-Report 

Hope this helps.