I'm trying to embed Google's "write a review" widget into my website. Much like what Podium.com does.
They host a page and load an iframe with the src:
https://www.google.com/maps/api/js/ReviewsService.LoadWriteWidget?key=THEIR_API_KEY&pb=!2m1!1sChIJ6VFjYpqa9YgREIJTX-XLyoE!3shttps%3A%2F%2Ftheir-url.com!5sen&cb=37369878
This renders the widget like so:

I dug into their html source and it appears they're using the Google Places Reviews Widget. I searched Google and Google Developers for "Google Places Reviews Widget" which returns results:
However, the links go to a 404 page:
- https://developers.google.com/places/reviews/reference
- https://developers.google.com/places/reviews/widgets
I've replicated what Podium is doing on my own page using my API key. However, the widget doesn't display. I don't get any errors, the iframe loads some scripts and some hidden html elements, but doesn't render the full widget.
Is this an API or feature that I'm unable to access? Has anyone implemented something similar?
