Secure Prezi URL

We have several faculty members and staff (myself included) who use Prezi regularly. We have regularly EDU Enjoy accounts.  In order to embed Prezis into our LMS (Sakai) and our survey system (Qualtrics), the URL for the Prezi needs to be secure (start with https not http). I seem to remember in the past that our Prezis were secure and started with https, but now, they all start with http and will not work properly with our LMS and survey software.  How to we get a URL for our Prezis that is secure (https)?

Thanks,
Mike Camden