Hi,
Thanks for reporting this and welcome to the GitLab forum 
I cannot reproduce what you are seeing. I’ve been browsing that page lately, with either Firefox and Chromium, and I can still see the form (I’ve just double-checked now).
I’m thinking perhaps you have something on your side that’s blocking the rendering of the form. Doing a search for “‘MktoForms2’ is not defined” returns some results with folks experiencing similar issues on other sites.
As per your question of where to report issues on the site, there’s a link to the issue tracker on the forum’s welcome page.
I hope this helps!